diff --git a/pkg/front_end/lib/src/fasta/source/source_loader.dart b/pkg/front_end/lib/src/fasta/source/source_loader.dart
index 16123b0cf36..8ab70e9257a 100644
--- a/pkg/front_end/lib/src/fasta/source/source_loader.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_loader.dart
@@ -1547,8 +1547,6 @@ _asyncErrorWrapperHelper(continuation) {}
 
 void _asyncStarMoveNextHelper(var stream) {}
 
-_asyncStackTraceHelper(async_op) {}
-
 _asyncThenWrapperHelper(continuation) {}
 
 _awaitHelper(object, thenCallback, errorCallback, awaiter) {}
diff --git a/pkg/front_end/test/flutter_gallery_leak_tester.dart b/pkg/front_end/test/flutter_gallery_leak_tester.dart
index 033b59a51e8..f8f32f46a3c 100644
--- a/pkg/front_end/test/flutter_gallery_leak_tester.dart
+++ b/pkg/front_end/test/flutter_gallery_leak_tester.dart
@@ -179,7 +179,6 @@ main(List<String> args) async {
     "--incremental",
     "--target=flutter",
     "--debugger-module-names",
-    "-Ddart.developer.causal_async_stacks=true",
     "--output-dill",
     "$rootPath/flutter_server_tmp.dill",
     "--packages",
diff --git a/pkg/front_end/testcases/extensions/async_extensions.dart.strong.transformed.expect b/pkg/front_end/testcases/extensions/async_extensions.dart.strong.transformed.expect
index 36fe6ad938a..2fab1ffd9a7 100644
--- a/pkg/front_end/testcases/extensions/async_extensions.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/extensions/async_extensions.dart.strong.transformed.expect
@@ -29,7 +29,6 @@ static method Extension|asyncMethod(final core::int* #this) → dynamic /* origi
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -44,7 +43,6 @@ static method Extension|asyncMethod(final core::int* #this) → dynamic /* origi
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -56,7 +54,6 @@ static method Extension|get#asyncMethod(final core::int* #this) → () →* dyna
 static method Extension|asyncStarMethod(final core::int* #this) → dynamic /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -74,7 +71,6 @@ static method Extension|asyncStarMethod(final core::int* #this) → dynamic /* o
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
diff --git a/pkg/front_end/testcases/extensions/deferred_explicit_access.dart.strong.transformed.expect b/pkg/front_end/testcases/extensions/deferred_explicit_access.dart.strong.transformed.expect
index 580ca3c6784..cacce17c484 100644
--- a/pkg/front_end/testcases/extensions/deferred_explicit_access.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/extensions/deferred_explicit_access.dart.strong.transformed.expect
@@ -18,7 +18,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -45,7 +44,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -102,4 +100,4 @@ Extra constant evaluation status:
 Evaluated: VariableGet @ org-dartlang-testcase:///deferred_explicit_access.dart:12:31 -> IntConstant(0)
 Evaluated: VariableGet @ org-dartlang-testcase:///deferred_explicit_access.dart:12:45 -> IntConstant(42)
 Evaluated: VariableGet @ org-dartlang-testcase:///deferred_explicit_access.dart:12:45 -> IntConstant(42)
-Extra constant evaluation: evaluated: 96, effectively constant: 3
+Extra constant evaluation: evaluated: 93, effectively constant: 3
diff --git a/pkg/front_end/testcases/extensions/deferred_import_hidden.dart.strong.transformed.expect b/pkg/front_end/testcases/extensions/deferred_import_hidden.dart.strong.transformed.expect
index 187e9da54ab..c43e5ff8308 100644
--- a/pkg/front_end/testcases/extensions/deferred_import_hidden.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/extensions/deferred_import_hidden.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/async_function.dart.strong.transformed.expect b/pkg/front_end/testcases/general/async_function.dart.strong.transformed.expect
index 33824858a52..33ab33fa0e5 100644
--- a/pkg/front_end/testcases/general/async_function.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/async_function.dart.strong.transformed.expect
@@ -11,7 +11,6 @@ static method asyncString() → asy::Future<core::String*>* /* originally async
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -29,7 +28,6 @@ static method asyncString() → asy::Future<core::String*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -40,7 +38,6 @@ static method asyncString2() → asy::Future<core::String*>* /* originally async
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -58,7 +55,6 @@ static method asyncString2() → asy::Future<core::String*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -110,7 +106,6 @@ static method syncStarString2() → core::Iterable<core::String*>* /* originally
 static method asyncStarString() → asy::Stream<core::String*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::String*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -144,7 +139,6 @@ static method asyncStarString() → asy::Stream<core::String*>* /* originally as
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::String*>(:async_op);
@@ -154,7 +148,6 @@ static method asyncStarString() → asy::Stream<core::String*>* /* originally as
 static method asyncStarString2() → asy::Stream<core::String*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::String*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -179,7 +172,6 @@ static method asyncStarString2() → asy::Stream<core::String*>* /* originally a
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::String*>(:async_op);
@@ -190,7 +182,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -209,7 +200,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/async_nested.dart.strong.transformed.expect b/pkg/front_end/testcases/general/async_nested.dart.strong.transformed.expect
index 772b4689011..78818d90767 100644
--- a/pkg/front_end/testcases/general/async_nested.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/async_nested.dart.strong.transformed.expect
@@ -31,7 +31,6 @@ static method main() → void /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -69,7 +68,6 @@ static method main() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/await.dart.strong.transformed.expect b/pkg/front_end/testcases/general/await.dart.strong.transformed.expect
index 9bac1f24f63..04a6af0b337 100644
--- a/pkg/front_end/testcases/general/await.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/await.dart.strong.transformed.expect
@@ -8,7 +8,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -27,7 +26,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/await_complex.dart.strong.transformed.expect b/pkg/front_end/testcases/general/await_complex.dart.strong.transformed.expect
index d6a8b9513aa..8b69c50f675 100644
--- a/pkg/front_end/testcases/general/await_complex.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/await_complex.dart.strong.transformed.expect
@@ -60,7 +60,6 @@ static method staticMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -107,7 +106,6 @@ static method staticMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -118,7 +116,6 @@ static method topLevelMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -160,7 +157,6 @@ static method topLevelMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -171,7 +167,6 @@ static method instanceMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -214,7 +209,6 @@ static method instanceMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -225,7 +219,6 @@ static method others() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -268,7 +261,6 @@ static method others() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -279,7 +271,6 @@ static method conditionals() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -342,7 +333,6 @@ static method conditionals() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -353,7 +343,6 @@ static method asserts() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -417,7 +406,6 @@ static method asserts() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -428,7 +416,6 @@ static method controlFlow() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -562,7 +549,6 @@ static method controlFlow() → dynamic /* originally async */ {
                 final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
                 core::bool* :is_sync = false;
                 FutureOr<dynamic>* :return_value;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -582,7 +568,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
                     asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :async_op.call();
@@ -594,7 +579,6 @@ static method controlFlow() → dynamic /* originally async */ {
                 final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
                 core::bool* :is_sync = false;
                 FutureOr<dynamic>* :return_value;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -612,7 +596,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
                     asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :async_op.call();
@@ -623,7 +606,6 @@ static method controlFlow() → dynamic /* originally async */ {
               function testStream1() → asy::Stream<core::int*>* /* originally async* */ {
                 asy::_AsyncStarStreamController<core::int*>* :controller;
                 dynamic :controller_stream;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -649,7 +631,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   finally {
                     :controller.{asy::_AsyncStarStreamController::close}();
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -662,7 +643,6 @@ static method controlFlow() → dynamic /* originally async */ {
               function testStream2() → asy::Stream<core::int*>* /* originally async* */ {
                 asy::_AsyncStarStreamController<core::int*>* :controller;
                 dynamic :controller_stream;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -688,7 +668,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   finally {
                     :controller.{asy::_AsyncStarStreamController::close}();
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -708,7 +687,6 @@ static method controlFlow() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -719,7 +697,6 @@ static method future<T extends core::Object* = dynamic>(self::future::T* value)
   final asy::_Future<self::future::T*>* :async_future = new asy::_Future::•<self::future::T*>();
   core::bool* :is_sync = false;
   FutureOr<self::future::T*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -737,7 +714,6 @@ static method future<T extends core::Object* = dynamic>(self::future::T* value)
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -749,7 +725,6 @@ static method id<T extends core::Object* = dynamic>(self::id::T* value) → Futu
 static method intStream() → asy::Stream<core::int*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::int*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -774,7 +749,6 @@ static method intStream() → asy::Stream<core::int*>* /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -785,7 +759,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -818,7 +791,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/await_in_cascade.dart.strong.transformed.expect b/pkg/front_end/testcases/general/await_in_cascade.dart.strong.transformed.expect
index fe03b1d3d95..e178bdfa0a2 100644
--- a/pkg/front_end/testcases/general/await_in_cascade.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/await_in_cascade.dart.strong.transformed.expect
@@ -14,7 +14,6 @@ class C extends core::Object {
     final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
     core::bool* :is_sync = false;
     FutureOr<core::List<core::int*>*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -47,7 +45,6 @@ class C extends core::Object {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -65,7 +62,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -87,7 +83,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -106,7 +101,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/bug33196.dart.strong.transformed.expect b/pkg/front_end/testcases/general/bug33196.dart.strong.transformed.expect
index fe416ab538d..ea1347ad1bf 100644
--- a/pkg/front_end/testcases/general/bug33196.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/bug33196.dart.strong.transformed.expect
@@ -13,7 +13,6 @@ static method returnsString() → FutureOr<core::String*>* /* originally async *
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method returnsString() → FutureOr<core::String*>* /* originally async *
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/bug33206.dart.strong.transformed.expect b/pkg/front_end/testcases/general/bug33206.dart.strong.transformed.expect
index 389811c83c6..b800d2a9483 100644
--- a/pkg/front_end/testcases/general/bug33206.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/bug33206.dart.strong.transformed.expect
@@ -44,7 +44,6 @@ static method f1() → asy::Future<core::List<core::Object*>*>* /* originally as
   final asy::_Future<core::List<core::Object*>*>* :async_future = new asy::_Future::•<core::List<core::Object*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::Object*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -62,7 +61,6 @@ static method f1() → asy::Future<core::List<core::Object*>*>* /* originally as
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -75,7 +73,6 @@ static method f3() → asy::Future<core::Object*>* /* originally async */ {
   final asy::_Future<core::Object*>* :async_future = new asy::_Future::•<core::Object*>();
   core::bool* :is_sync = false;
   FutureOr<core::Object*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -93,7 +90,6 @@ static method f3() → asy::Future<core::Object*>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -104,7 +100,6 @@ static method foo() → asy::Future<self::X*>* /* originally async */ {
   final asy::_Future<self::X*>* :async_future = new asy::_Future::•<self::X*>();
   core::bool* :is_sync = false;
   FutureOr<self::X*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -131,7 +126,6 @@ static method foo() → asy::Future<self::X*>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -142,7 +136,6 @@ static method main() → asy::Future<void>* /* originally async */ {
   final asy::_Future<void>* :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -161,7 +154,6 @@ static method main() → asy::Future<void>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/check_deferred_before_args2.dart.strong.transformed.expect b/pkg/front_end/testcases/general/check_deferred_before_args2.dart.strong.transformed.expect
index ad4521b4fcb..fd3b4a6a6bc 100644
--- a/pkg/front_end/testcases/general/check_deferred_before_args2.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/check_deferred_before_args2.dart.strong.transformed.expect
@@ -11,7 +11,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/control_flow_collection_inference.dart.strong.transformed.expect b/pkg/front_end/testcases/general/control_flow_collection_inference.dart.strong.transformed.expect
index 898ae5231c5..8b93516b397 100644
--- a/pkg/front_end/testcases/general/control_flow_collection_inference.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/control_flow_collection_inference.dart.strong.transformed.expect
@@ -2342,7 +2342,6 @@ static method testForElementErrors(core::Map<core::int*, core::int*>* map, core:
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -2893,7 +2892,6 @@ static method testForElementErrors(core::Map<core::int*, core::int*>* map, core:
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/error_recovery/empty_await_for.dart.strong.transformed.expect b/pkg/front_end/testcases/general/error_recovery/empty_await_for.dart.strong.transformed.expect
index caf60f4277a..8ab3f4cd9e0 100644
--- a/pkg/front_end/testcases/general/error_recovery/empty_await_for.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/error_recovery/empty_await_for.dart.strong.transformed.expect
@@ -20,7 +20,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -67,7 +66,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/flutter_issue64155.dart.strong.transformed.expect b/pkg/front_end/testcases/general/flutter_issue64155.dart.strong.transformed.expect
index 23d120e2f8c..97f034acc79 100644
--- a/pkg/front_end/testcases/general/flutter_issue64155.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/flutter_issue64155.dart.strong.transformed.expect
@@ -9,7 +9,6 @@ abstract class TestMixin<R extends core::Object* = dynamic, T extends core::Obje
     final asy::_Future<self::TestMixin::T*>* :async_future = new asy::_Future::•<self::TestMixin::T*>();
     core::bool* :is_sync = false;
     FutureOr<self::TestMixin::T*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -45,7 +44,6 @@ abstract class TestMixin<R extends core::Object* = dynamic, T extends core::Obje
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -129,7 +127,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
     core::bool* :is_sync = false;
     FutureOr<core::String*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -165,7 +162,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -200,7 +196,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
     core::bool* :is_sync = false;
     FutureOr<core::String*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -236,7 +231,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/general/future_or_test.dart.strong.transformed.expect b/pkg/front_end/testcases/general/future_or_test.dart.strong.transformed.expect
index a4ac3f43f11..f62a5eb1b38 100644
--- a/pkg/front_end/testcases/general/future_or_test.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/future_or_test.dart.strong.transformed.expect
@@ -31,7 +31,6 @@ class B extends core::Object {
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -49,7 +48,6 @@ class B extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -76,7 +74,6 @@ class C extends core::Object {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -94,7 +91,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/general/future_return.dart.strong.transformed.expect b/pkg/front_end/testcases/general/future_return.dart.strong.transformed.expect
index 6f96292629e..059106c7598 100644
--- a/pkg/front_end/testcases/general/future_return.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/future_return.dart.strong.transformed.expect
@@ -46,7 +46,6 @@ static method returnClass() → self::Class* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -64,7 +63,6 @@ static method returnClass() → self::Class* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -75,7 +73,6 @@ static method returnFutureClass() → asy::Future<self::Class*>* /* originally a
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -93,7 +90,6 @@ static method returnFutureClass() → asy::Future<self::Class*>* /* originally a
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -104,7 +100,6 @@ static method returnFutureOrClass() → FutureOr<self::Class*>* /* originally as
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -122,7 +117,6 @@ static method returnFutureOrClass() → FutureOr<self::Class*>* /* originally as
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -133,7 +127,6 @@ static method returnClassFromDynamic() → self::Class* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -151,7 +144,6 @@ static method returnClassFromDynamic() → self::Class* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -162,7 +154,6 @@ static method returnFutureClassDynamic() → asy::Future<self::Class*>* /* origi
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -180,7 +171,6 @@ static method returnFutureClassDynamic() → asy::Future<self::Class*>* /* origi
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -191,7 +181,6 @@ static method returnFutureOrClassDynamic() → FutureOr<self::Class*>* /* origin
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -209,7 +198,6 @@ static method returnFutureOrClassDynamic() → FutureOr<self::Class*>* /* origin
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -220,7 +208,6 @@ static method returnClassFromFutureClass() → self::Class* /* originally async
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -238,7 +225,6 @@ static method returnClassFromFutureClass() → self::Class* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -249,7 +235,6 @@ static method returnFutureClassFromFutureClass() → asy::Future<self::Class*>*
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -267,7 +252,6 @@ static method returnFutureClassFromFutureClass() → asy::Future<self::Class*>*
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -278,7 +262,6 @@ static method returnFutureOrClassFromFutureClass() → FutureOr<self::Class*>* /
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -296,7 +279,6 @@ static method returnFutureOrClassFromFutureClass() → FutureOr<self::Class*>* /
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -307,7 +289,6 @@ static method returnClassFromFutureOrClass() → self::Class* /* originally asyn
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -325,7 +306,6 @@ static method returnClassFromFutureOrClass() → self::Class* /* originally asyn
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -336,7 +316,6 @@ static method returnFutureClassFromFutureOrClass() → asy::Future<self::Class*>
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -354,7 +333,6 @@ static method returnFutureClassFromFutureOrClass() → asy::Future<self::Class*>
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -365,7 +343,6 @@ static method returnFutureOrClassFromFutureOrClass() → FutureOr<self::Class*>*
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -383,7 +360,6 @@ static method returnFutureOrClassFromFutureOrClass() → FutureOr<self::Class*>*
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -394,7 +370,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -435,7 +410,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/issue40662.dart.strong.transformed.expect b/pkg/front_end/testcases/general/issue40662.dart.strong.transformed.expect
index d7e7ecacc4f..58436b74016 100644
--- a/pkg/front_end/testcases/general/issue40662.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/issue40662.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ static method foo(core::int* x) → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -45,7 +44,6 @@ static method foo(core::int* x) → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -56,7 +54,6 @@ static method main() → void /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -76,7 +73,6 @@ static method main() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -92,4 +88,4 @@ static method expect(dynamic expected, dynamic actual) → dynamic {
 Extra constant evaluation status:
 Evaluated: MethodInvocation @ org-dartlang-testcase:///issue40662.dart:8:10 -> IntConstant(-1)
 Evaluated: MethodInvocation @ org-dartlang-testcase:///issue40662.dart:9:10 -> IntConstant(-1)
-Extra constant evaluation: evaluated: 101, effectively constant: 2
+Extra constant evaluation: evaluated: 95, effectively constant: 2
diff --git a/pkg/front_end/testcases/general/issue42615.dart.strong.transformed.expect b/pkg/front_end/testcases/general/issue42615.dart.strong.transformed.expect
index 5550a8f1c4c..3144af6be8d 100644
--- a/pkg/front_end/testcases/general/issue42615.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/issue42615.dart.strong.transformed.expect
@@ -27,7 +27,6 @@ static method main() → dynamic {
     final asy::_Future<core::List<dynamic>*>* :async_future = new asy::_Future::•<core::List<dynamic>*>();
     core::bool* :is_sync = false;
     FutureOr<core::List<dynamic>*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -45,7 +44,6 @@ static method main() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/general/no_such_method_forwarder.dart.strong.transformed.expect b/pkg/front_end/testcases/general/no_such_method_forwarder.dart.strong.transformed.expect
index bb66d2fc365..72d4454738b 100644
--- a/pkg/front_end/testcases/general/no_such_method_forwarder.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/no_such_method_forwarder.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ class X extends core::Object {
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -32,7 +31,6 @@ class X extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/general/regression_flutter51828.dart.strong.transformed.expect b/pkg/front_end/testcases/general/regression_flutter51828.dart.strong.transformed.expect
index 30085d78c05..442d3ae2ecb 100644
--- a/pkg/front_end/testcases/general/regression_flutter51828.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/regression_flutter51828.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ class A extends core::Object {
     final asy::_Future<void>* :async_future = new asy::_Future::•<void>();
     core::bool* :is_sync = false;
     FutureOr<void>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -27,7 +26,6 @@ class A extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -53,7 +51,6 @@ class B extends core::Object {
     final asy::_Future<void>* :async_future = new asy::_Future::•<void>();
     core::bool* :is_sync = false;
     FutureOr<void>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -68,7 +65,6 @@ class B extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -90,7 +86,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -116,7 +111,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general/statements.dart.strong.transformed.expect b/pkg/front_end/testcases/general/statements.dart.strong.transformed.expect
index a02506d4df5..91dfee37d2c 100644
--- a/pkg/front_end/testcases/general/statements.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/statements.dart.strong.transformed.expect
@@ -15,7 +15,6 @@ static method foo() → dynamic {
 static method bar(dynamic d) → dynamic /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -69,7 +68,6 @@ static method bar(dynamic d) → dynamic /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
diff --git a/pkg/front_end/testcases/general/stream_future.dart.strong.transformed.expect b/pkg/front_end/testcases/general/stream_future.dart.strong.transformed.expect
index 97bf589cea1..f76844425e3 100644
--- a/pkg/front_end/testcases/general/stream_future.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/general/stream_future.dart.strong.transformed.expect
@@ -38,7 +38,6 @@ static method returnFutureDynamic() → asy::Future<dynamic>* /* originally asyn
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -56,7 +55,6 @@ static method returnFutureDynamic() → asy::Future<dynamic>* /* originally asyn
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -67,7 +65,6 @@ static method returnFutureClass() → asy::Future<self::Class*>* /* originally a
   final asy::_Future<self::Class*>* :async_future = new asy::_Future::•<self::Class*>();
   core::bool* :is_sync = false;
   FutureOr<self::Class*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -85,7 +82,6 @@ static method returnFutureClass() → asy::Future<self::Class*>* /* originally a
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -95,7 +91,6 @@ static method returnFutureClass() → asy::Future<self::Class*>* /* originally a
 static method error() → asy::Stream<FutureOr<self::Class*>*>* /* originally async* */ {
   asy::_AsyncStarStreamController<FutureOr<self::Class*>*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -124,7 +119,6 @@ static method error() → asy::Stream<FutureOr<self::Class*>*>* /* originally as
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<FutureOr<self::Class*>*>(:async_op);
@@ -134,7 +128,6 @@ static method error() → asy::Stream<FutureOr<self::Class*>*>* /* originally as
 static method stream() → asy::Stream<FutureOr<self::Class*>*>* /* originally async* */ {
   asy::_AsyncStarStreamController<FutureOr<self::Class*>*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -167,7 +160,6 @@ static method stream() → asy::Stream<FutureOr<self::Class*>*>* /* originally a
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<FutureOr<self::Class*>*>(:async_op);
@@ -178,7 +170,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -221,7 +212,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/async_function.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/async_function.dart.weak.transformed.expect
index 33824858a52..33ab33fa0e5 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/async_function.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/async_function.dart.weak.transformed.expect
@@ -11,7 +11,6 @@ static method asyncString() → asy::Future<core::String*>* /* originally async
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -29,7 +28,6 @@ static method asyncString() → asy::Future<core::String*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -40,7 +38,6 @@ static method asyncString2() → asy::Future<core::String*>* /* originally async
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -58,7 +55,6 @@ static method asyncString2() → asy::Future<core::String*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -110,7 +106,6 @@ static method syncStarString2() → core::Iterable<core::String*>* /* originally
 static method asyncStarString() → asy::Stream<core::String*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::String*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -144,7 +139,6 @@ static method asyncStarString() → asy::Stream<core::String*>* /* originally as
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::String*>(:async_op);
@@ -154,7 +148,6 @@ static method asyncStarString() → asy::Stream<core::String*>* /* originally as
 static method asyncStarString2() → asy::Stream<core::String*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::String*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -179,7 +172,6 @@ static method asyncStarString2() → asy::Stream<core::String*>* /* originally a
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::String*>(:async_op);
@@ -190,7 +182,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -209,7 +200,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/async_nested.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/async_nested.dart.weak.transformed.expect
index 772b4689011..78818d90767 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/async_nested.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/async_nested.dart.weak.transformed.expect
@@ -31,7 +31,6 @@ static method main() → void /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -69,7 +68,6 @@ static method main() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/await.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/await.dart.weak.transformed.expect
index 9bac1f24f63..04a6af0b337 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/await.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/await.dart.weak.transformed.expect
@@ -8,7 +8,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -27,7 +26,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/await_complex.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/await_complex.dart.weak.transformed.expect
index d6a8b9513aa..8b69c50f675 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/await_complex.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/await_complex.dart.weak.transformed.expect
@@ -60,7 +60,6 @@ static method staticMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -107,7 +106,6 @@ static method staticMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -118,7 +116,6 @@ static method topLevelMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -160,7 +157,6 @@ static method topLevelMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -171,7 +167,6 @@ static method instanceMembers() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -214,7 +209,6 @@ static method instanceMembers() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -225,7 +219,6 @@ static method others() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -268,7 +261,6 @@ static method others() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -279,7 +271,6 @@ static method conditionals() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -342,7 +333,6 @@ static method conditionals() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -353,7 +343,6 @@ static method asserts() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -417,7 +406,6 @@ static method asserts() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -428,7 +416,6 @@ static method controlFlow() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -562,7 +549,6 @@ static method controlFlow() → dynamic /* originally async */ {
                 final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
                 core::bool* :is_sync = false;
                 FutureOr<dynamic>* :return_value;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -582,7 +568,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
                     asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :async_op.call();
@@ -594,7 +579,6 @@ static method controlFlow() → dynamic /* originally async */ {
                 final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
                 core::bool* :is_sync = false;
                 FutureOr<dynamic>* :return_value;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -612,7 +596,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
                     asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :async_op.call();
@@ -623,7 +606,6 @@ static method controlFlow() → dynamic /* originally async */ {
               function testStream1() → asy::Stream<core::int*>* /* originally async* */ {
                 asy::_AsyncStarStreamController<core::int*>* :controller;
                 dynamic :controller_stream;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -649,7 +631,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   finally {
                     :controller.{asy::_AsyncStarStreamController::close}();
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -662,7 +643,6 @@ static method controlFlow() → dynamic /* originally async */ {
               function testStream2() → asy::Stream<core::int*>* /* originally async* */ {
                 asy::_AsyncStarStreamController<core::int*>* :controller;
                 dynamic :controller_stream;
-                dynamic :async_stack_trace;
                 (dynamic) →* dynamic :async_op_then;
                 (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
                 core::int* :await_jump_var = 0;
@@ -688,7 +668,6 @@ static method controlFlow() → dynamic /* originally async */ {
                   finally {
                     :controller.{asy::_AsyncStarStreamController::close}();
                   }
-                :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
                 :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
                 :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
                 :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -708,7 +687,6 @@ static method controlFlow() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -719,7 +697,6 @@ static method future<T extends core::Object* = dynamic>(self::future::T* value)
   final asy::_Future<self::future::T*>* :async_future = new asy::_Future::•<self::future::T*>();
   core::bool* :is_sync = false;
   FutureOr<self::future::T*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -737,7 +714,6 @@ static method future<T extends core::Object* = dynamic>(self::future::T* value)
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -749,7 +725,6 @@ static method id<T extends core::Object* = dynamic>(self::id::T* value) → Futu
 static method intStream() → asy::Stream<core::int*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::int*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -774,7 +749,6 @@ static method intStream() → asy::Stream<core::int*>* /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
@@ -785,7 +759,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -818,7 +791,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/await_in_cascade.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/await_in_cascade.dart.weak.transformed.expect
index fe03b1d3d95..e178bdfa0a2 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/await_in_cascade.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/await_in_cascade.dart.weak.transformed.expect
@@ -14,7 +14,6 @@ class C extends core::Object {
     final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
     core::bool* :is_sync = false;
     FutureOr<core::List<core::int*>*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -47,7 +45,6 @@ class C extends core::Object {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -65,7 +62,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -87,7 +83,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -106,7 +101,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/bug33196.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/bug33196.dart.weak.transformed.expect
index fe416ab538d..ea1347ad1bf 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/bug33196.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/bug33196.dart.weak.transformed.expect
@@ -13,7 +13,6 @@ static method returnsString() → FutureOr<core::String*>* /* originally async *
   final asy::_Future<core::String*>* :async_future = new asy::_Future::•<core::String*>();
   core::bool* :is_sync = false;
   FutureOr<core::String*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method returnsString() → FutureOr<core::String*>* /* originally async *
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/bug33206.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/bug33206.dart.weak.transformed.expect
index 389811c83c6..b800d2a9483 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/bug33206.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/bug33206.dart.weak.transformed.expect
@@ -44,7 +44,6 @@ static method f1() → asy::Future<core::List<core::Object*>*>* /* originally as
   final asy::_Future<core::List<core::Object*>*>* :async_future = new asy::_Future::•<core::List<core::Object*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::Object*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -62,7 +61,6 @@ static method f1() → asy::Future<core::List<core::Object*>*>* /* originally as
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -75,7 +73,6 @@ static method f3() → asy::Future<core::Object*>* /* originally async */ {
   final asy::_Future<core::Object*>* :async_future = new asy::_Future::•<core::Object*>();
   core::bool* :is_sync = false;
   FutureOr<core::Object*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -93,7 +90,6 @@ static method f3() → asy::Future<core::Object*>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -104,7 +100,6 @@ static method foo() → asy::Future<self::X*>* /* originally async */ {
   final asy::_Future<self::X*>* :async_future = new asy::_Future::•<self::X*>();
   core::bool* :is_sync = false;
   FutureOr<self::X*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -131,7 +126,6 @@ static method foo() → asy::Future<self::X*>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -142,7 +136,6 @@ static method main() → asy::Future<void>* /* originally async */ {
   final asy::_Future<void>* :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -161,7 +154,6 @@ static method main() → asy::Future<void>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/check_deferred_before_args2.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/check_deferred_before_args2.dart.weak.transformed.expect
index ad4521b4fcb..fd3b4a6a6bc 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/check_deferred_before_args2.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/check_deferred_before_args2.dart.weak.transformed.expect
@@ -11,7 +11,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/control_flow_collection_inference.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/control_flow_collection_inference.dart.weak.transformed.expect
index b843b323587..d7f35a943b3 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/control_flow_collection_inference.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/control_flow_collection_inference.dart.weak.transformed.expect
@@ -2342,7 +2342,6 @@ static method testForElementErrors(core::Map<core::int*, core::int*>* map, core:
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -2893,7 +2892,6 @@ static method testForElementErrors(core::Map<core::int*, core::int*>* map, core:
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/future_or_test.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/future_or_test.dart.weak.transformed.expect
index a4ac3f43f11..f62a5eb1b38 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/future_or_test.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/future_or_test.dart.weak.transformed.expect
@@ -31,7 +31,6 @@ class B extends core::Object {
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -49,7 +48,6 @@ class B extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -76,7 +74,6 @@ class C extends core::Object {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -94,7 +91,6 @@ class C extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/statements.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/statements.dart.weak.transformed.expect
index a02506d4df5..91dfee37d2c 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/statements.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/statements.dart.weak.transformed.expect
@@ -15,7 +15,6 @@ static method foo() → dynamic {
 static method bar(dynamic d) → dynamic /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -69,7 +68,6 @@ static method bar(dynamic d) → dynamic /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
diff --git a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.1.expect b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.1.expect
index 32da763cbef..e2cb288754d 100644
--- a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.1.expect
+++ b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.1.expect
@@ -5,7 +5,6 @@ library from "org-dartlang-test:///libA.dart" as libA {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -26,7 +25,6 @@ library from "org-dartlang-test:///libA.dart" as libA {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -59,7 +57,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -79,7 +76,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.2.expect b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.2.expect
index 0fabe895d01..6ef77a2d122 100644
--- a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.2.expect
+++ b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_3.yaml.world.2.expect
@@ -5,7 +5,6 @@ library from "org-dartlang-test:///libA.dart" as libA {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -26,7 +25,6 @@ library from "org-dartlang-test:///libA.dart" as libA {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -59,7 +57,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -80,7 +77,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.1.expect b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.1.expect
index e8c7c9a3110..824f20e6f9f 100644
--- a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.1.expect
+++ b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.1.expect
@@ -23,7 +23,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -43,7 +42,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -54,7 +52,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -75,7 +72,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.2.expect b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.2.expect
index af9c5da1a4d..44652d17cea 100644
--- a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.2.expect
+++ b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.2.expect
@@ -23,7 +23,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -43,7 +42,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -54,7 +52,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -75,7 +72,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.3.expect b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.3.expect
index abf2025f81a..99415d40fb6 100644
--- a/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.3.expect
+++ b/pkg/front_end/testcases/incremental_initialize_from_dill/no_outline_change_5.yaml.world.3.expect
@@ -23,7 +23,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -44,7 +43,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -55,7 +53,6 @@ library from "org-dartlang-test:///main.dart" as main {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -76,7 +73,6 @@ library from "org-dartlang-test:///main.dart" as main {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/async_await.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/async_await.dart.strong.transformed.expect
index 487e430449c..d56811d4132 100644
--- a/pkg/front_end/testcases/inference/async_await.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/async_await.dart.strong.transformed.expect
@@ -30,7 +30,6 @@ static method test() → void /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -54,7 +53,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
           core::bool* :is_sync = false;
           FutureOr<core::int*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -72,7 +70,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -83,7 +80,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
           core::bool* :is_sync = false;
           FutureOr<core::int*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -101,7 +97,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -112,7 +107,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<asy::Future<core::int*>*>* :async_future = new asy::_Future::•<asy::Future<core::int*>*>();
           core::bool* :is_sync = false;
           FutureOr<asy::Future<core::int*>*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -130,7 +124,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -141,7 +134,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<FutureOr<core::int*>*>* :async_future = new asy::_Future::•<FutureOr<core::int*>*>();
           core::bool* :is_sync = false;
           FutureOr<FutureOr<core::int*>*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -159,7 +151,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -170,7 +161,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<self::MyFuture*>* :async_future = new asy::_Future::•<self::MyFuture*>();
           core::bool* :is_sync = false;
           FutureOr<self::MyFuture*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -188,7 +178,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -199,7 +188,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
           core::bool* :is_sync = false;
           FutureOr<core::int*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -217,7 +205,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -228,7 +215,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<asy::Future<core::int*>*>* :async_future = new asy::_Future::•<asy::Future<core::int*>*>();
           core::bool* :is_sync = false;
           FutureOr<asy::Future<core::int*>*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -246,7 +232,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -257,7 +242,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<FutureOr<core::int*>*>* :async_future = new asy::_Future::•<FutureOr<core::int*>*>();
           core::bool* :is_sync = false;
           FutureOr<FutureOr<core::int*>*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -275,7 +259,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -286,7 +269,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<self::MyFuture*>* :async_future = new asy::_Future::•<self::MyFuture*>();
           core::bool* :is_sync = false;
           FutureOr<self::MyFuture*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -304,7 +286,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -315,7 +296,6 @@ static method test() → void /* originally async */ {
           final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
           core::bool* :is_sync = false;
           FutureOr<core::int*>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -333,7 +313,6 @@ static method test() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -367,7 +346,6 @@ static method test() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/async_closure_return_type_flatten.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/async_closure_return_type_flatten.dart.strong.transformed.expect
index e19b6bd377d..3a8bfa5c734 100644
--- a/pkg/front_end/testcases/inference/async_closure_return_type_flatten.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/async_closure_return_type_flatten.dart.strong.transformed.expect
@@ -11,7 +11,6 @@ static field () →* asy::Future<core::int*>* g = () → asy::Future<core::int*>
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -29,7 +28,6 @@ static field () →* asy::Future<core::int*>* g = () → asy::Future<core::int*>
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/async_closure_return_type_future.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/async_closure_return_type_future.dart.strong.transformed.expect
index e7ca87da58f..8e77c7590bb 100644
--- a/pkg/front_end/testcases/inference/async_closure_return_type_future.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/async_closure_return_type_future.dart.strong.transformed.expect
@@ -7,7 +7,6 @@ static field () →* asy::Future<core::int*>* f = () → asy::Future<core::int*>
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -25,7 +24,6 @@ static field () →* asy::Future<core::int*>* f = () → asy::Future<core::int*>
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/async_closure_return_type_future_or.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/async_closure_return_type_future_or.dart.strong.transformed.expect
index 191fffbbb8d..b678b0dc7a8 100644
--- a/pkg/front_end/testcases/inference/async_closure_return_type_future_or.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/async_closure_return_type_future_or.dart.strong.transformed.expect
@@ -11,7 +11,6 @@ static field () →* asy::Future<core::int*>* g = () → asy::Future<core::int*>
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -29,7 +28,6 @@ static field () →* asy::Future<core::int*>* g = () → asy::Future<core::int*>
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_futures.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_futures.dart.strong.transformed.expect
index 04cb4b43fc0..5bac272a884 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_futures.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_futures.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ static method test() → dynamic {
     final asy::_Future<core::num*>* :async_future = new asy::_Future::•<core::num*>();
     core::bool* :is_sync = false;
     FutureOr<core::num*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ static method test() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_values.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_values.dart.strong.transformed.expect
index a7b9b3d5722..6d91810b217 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_values.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_all_returns_are_values.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ static method test() → dynamic {
     final asy::_Future<core::num*>* :async_future = new asy::_Future::•<core::num*>();
     core::bool* :is_sync = false;
     FutureOr<core::num*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ static method test() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_mix_of_values_and_futures.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_mix_of_values_and_futures.dart.strong.transformed.expect
index 398dba41d77..5cd44bc29cf 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_mix_of_values_and_futures.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_mix_of_values_and_futures.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ static method test() → dynamic {
     final asy::_Future<core::num*>* :async_future = new asy::_Future::•<core::num*>();
     core::bool* :is_sync = false;
     FutureOr<core::num*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -36,7 +35,6 @@ static method test() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_star.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_star.dart.strong.transformed.expect
index a13fe6aef27..adbe9519927 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_async_star.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_async_star.dart.strong.transformed.expect
@@ -9,7 +9,6 @@ static method test() → dynamic {
   () →* asy::Stream<core::num*>* f = () → asy::Stream<core::num*>* /* originally async* */ {
     asy::_AsyncStarStreamController<core::num*>* :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -39,7 +38,6 @@ static method test() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<core::num*>(:async_op);
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async.dart.strong.transformed.expect
index 6215f3a8414..bd417fc6310 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -24,7 +23,6 @@ static method main() → dynamic /* originally async */ {
           final asy::_Future<Null>* :async_future = new asy::_Future::•<Null>();
           core::bool* :is_sync = false;
           FutureOr<Null>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -42,7 +40,6 @@ static method main() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -60,7 +57,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async_star.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async_star.dart.strong.transformed.expect
index a83d5ab9e7d..fa13ae6ce6f 100644
--- a/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async_star.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/block_bodied_lambdas_infer_bottom_async_star.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -23,7 +22,6 @@ static method main() → dynamic /* originally async */ {
         () →* asy::Stream<Null>* f = () → asy::Stream<Null>* /* originally async* */ {
           asy::_AsyncStarStreamController<Null>* :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -48,7 +46,6 @@ static method main() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<Null>(:async_op);
@@ -66,7 +63,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/downwards_inference_async_await.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/downwards_inference_async_await.dart.strong.transformed.expect
index c861eeeef53..1d08476c3f8 100644
--- a/pkg/front_end/testcases/inference/downwards_inference_async_await.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/downwards_inference_async_await.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method main() → asy::Future<dynamic>* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -32,7 +31,6 @@ static method main() → asy::Future<dynamic>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/downwards_inference_for_each.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/downwards_inference_for_each.dart.strong.transformed.expect
index 30e408618cd..313ed02235b 100644
--- a/pkg/front_end/testcases/inference/downwards_inference_for_each.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/downwards_inference_for_each.dart.strong.transformed.expect
@@ -63,7 +63,6 @@ static method f() → asy::Future<dynamic>* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -233,7 +232,6 @@ static method f() → asy::Future<dynamic>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -244,7 +242,6 @@ static method main() → asy::Future<dynamic>* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -327,7 +324,6 @@ static method main() → asy::Future<dynamic>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/downwards_inference_yield_yield_star.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/downwards_inference_yield_yield_star.dart.strong.transformed.expect
index 91c81029ed8..3f747b9b74e 100644
--- a/pkg/front_end/testcases/inference/downwards_inference_yield_yield_star.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/downwards_inference_yield_yield_star.dart.strong.transformed.expect
@@ -86,7 +86,6 @@ abstract class MyStream<T extends core::Object* = dynamic> extends asy::Stream<s
 static method foo() → asy::Stream<core::List<core::int*>*>* /* originally async* */ {
   asy::_AsyncStarStreamController<core::List<core::int*>*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -131,7 +130,6 @@ static method foo() → asy::Stream<core::List<core::int*>*>* /* originally asyn
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::List<core::int*>*>(:async_op);
diff --git a/pkg/front_end/testcases/inference/for_each_downcast_iterable.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/for_each_downcast_iterable.dart.strong.transformed.expect
index 7e9c9e0e15f..a832376d189 100644
--- a/pkg/front_end/testcases/inference/for_each_downcast_iterable.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/for_each_downcast_iterable.dart.strong.transformed.expect
@@ -8,7 +8,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -90,7 +89,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then.dart.strong.transformed.expect
index d5ab080b91c..99706f823a2 100644
--- a/pkg/front_end/testcases/inference/future_then.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_2.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_2.dart.strong.transformed.expect
index 4e59f53e982..780ffb76a21 100644
--- a/pkg/front_end/testcases/inference/future_then_2.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_2.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_3.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_3.dart.strong.transformed.expect
index d64e850232f..3b12a3e8b9b 100644
--- a/pkg/front_end/testcases/inference/future_then_3.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_3.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_4.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_4.dart.strong.transformed.expect
index 656e9a761c2..f715984547a 100644
--- a/pkg/front_end/testcases/inference/future_then_4.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_4.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_5.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_5.dart.strong.transformed.expect
index 5f08a169b52..8095cd99104 100644
--- a/pkg/front_end/testcases/inference/future_then_5.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_5.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_6.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_6.dart.strong.transformed.expect
index 6e05d10d844..2bb0e59a538 100644
--- a/pkg/front_end/testcases/inference/future_then_6.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_6.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -59,7 +58,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -70,7 +68,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -90,7 +87,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -101,7 +97,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -119,7 +114,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +124,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -148,7 +141,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -163,7 +155,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -181,7 +172,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -192,7 +182,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional.dart.strong.transformed.expect
index 97390dc8dce..1b90060268e 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional_2.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional_2.dart.strong.transformed.expect
index 7e7583eda30..09ef6019d0a 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional_2.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional_2.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional_3.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional_3.dart.strong.transformed.expect
index b8e8643b7cf..97bec60c996 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional_3.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional_3.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional_4.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional_4.dart.strong.transformed.expect
index dbf053f7348..947f0928fb8 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional_4.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional_4.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional_5.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional_5.dart.strong.transformed.expect
index f0ab4cdabe5..1ea35fea527 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional_5.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional_5.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_conditional_6.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_conditional_6.dart.strong.transformed.expect
index 27e32cf3f13..8acc63154f2 100644
--- a/pkg/front_end/testcases/inference/future_then_conditional_6.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_conditional_6.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -77,7 +75,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -97,7 +94,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_then_ifNull.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_then_ifNull.dart.strong.transformed.expect
index 0ffe0859a0d..41975f1778c 100644
--- a/pkg/front_end/testcases/inference/future_then_ifNull.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_then_ifNull.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -67,7 +66,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -78,7 +76,6 @@ static method test() → void {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -98,7 +95,6 @@ static method test() → void {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_async_conditional.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_async_conditional.dart.strong.transformed.expect
index cf08d883002..2d0d430bf56 100644
--- a/pkg/front_end/testcases/inference/future_union_async_conditional.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_async_conditional.dart.strong.transformed.expect
@@ -36,7 +36,6 @@ static method g1(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -54,7 +53,6 @@ static method g1(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -65,7 +63,6 @@ static method g2(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -83,7 +80,6 @@ static method g2(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -94,7 +90,6 @@ static method g3(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -113,7 +108,6 @@ static method g3(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_async_conditional_2.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_async_conditional_2.dart.strong.transformed.expect
index eae973742ec..e4ad3808bc5 100644
--- a/pkg/front_end/testcases/inference/future_union_async_conditional_2.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_async_conditional_2.dart.strong.transformed.expect
@@ -36,7 +36,6 @@ static method g1(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -54,7 +53,6 @@ static method g1(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -65,7 +63,6 @@ static method g2(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -83,7 +80,6 @@ static method g2(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -94,7 +90,6 @@ static method g3(core::bool* x) → asy::Future<core::int*>* /* originally async
   final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
   core::bool* :is_sync = false;
   FutureOr<core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -113,7 +108,6 @@ static method g3(core::bool* x) → asy::Future<core::int*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards.dart.strong.transformed.expect
index b26d359a942..cdf55f7bd4e 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards.dart.strong.transformed.expect
@@ -48,7 +48,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -77,7 +75,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -95,7 +92,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards_2.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards_2.dart.strong.transformed.expect
index 223a03e56d4..3338e9b0e3a 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards_2.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards_2.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -57,7 +56,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -68,7 +66,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -86,7 +83,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards_3.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards_3.dart.strong.transformed.expect
index 083d7a2580a..d89cd97257d 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards_3.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards_3.dart.strong.transformed.expect
@@ -48,7 +48,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -77,7 +75,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -95,7 +92,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards_4.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards_4.dart.strong.transformed.expect
index 31ccfda2937..b7ad80aca62 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards_4.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards_4.dart.strong.transformed.expect
@@ -39,7 +39,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -57,7 +56,6 @@ static method g2() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -68,7 +66,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
   final asy::_Future<core::List<core::int*>*>* :async_future = new asy::_Future::•<core::List<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::List<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -86,7 +83,6 @@ static method g3() → asy::Future<core::List<core::int*>*>* /* originally async
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_future_return.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_future_return.dart.strong.transformed.expect
index 9eb70305e40..a59d7c80f4a 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_future_return.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_future_return.dart.strong.transformed.expect
@@ -25,7 +25,6 @@ static method foo() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -46,7 +45,6 @@ static method foo() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_generic_return.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_generic_return.dart.strong.transformed.expect
index b214c57c233..611598b07ba 100644
--- a/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_generic_return.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_downwards_generic_method_with_generic_return.dart.strong.transformed.expect
@@ -12,7 +12,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -32,7 +31,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/future_union_upwards_generic_methods.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/future_union_upwards_generic_methods.dart.strong.transformed.expect
index fee2dcd2c17..448d38f4673 100644
--- a/pkg/front_end/testcases/inference/future_union_upwards_generic_methods.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/future_union_upwards_generic_methods.dart.strong.transformed.expect
@@ -35,7 +35,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -61,7 +60,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/generator_closure.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/generator_closure.dart.strong.transformed.expect
index b1d5d536648..2f34a0b769f 100644
--- a/pkg/front_end/testcases/inference/generator_closure.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/generator_closure.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method main() → void {
   self::foo(() → asy::Stream<core::int*>* /* originally async* */ {
     asy::_AsyncStarStreamController<core::int*>* :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -39,7 +38,6 @@ static method main() → void {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
diff --git a/pkg/front_end/testcases/inference/infer_local_function_return_type.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/infer_local_function_return_type.dart.strong.transformed.expect
index c1b45ecb6b7..eeeccd277e0 100644
--- a/pkg/front_end/testcases/inference/infer_local_function_return_type.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/infer_local_function_return_type.dart.strong.transformed.expect
@@ -10,7 +10,6 @@ static method test() → dynamic {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -28,7 +27,6 @@ static method test() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -42,7 +40,6 @@ static method test() → dynamic {
     final asy::_Future<core::int*>* :async_future = new asy::_Future::•<core::int*>();
     core::bool* :is_sync = false;
     FutureOr<core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -60,7 +57,6 @@ static method test() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -87,7 +83,6 @@ static method test() → dynamic {
   function f5() → asy::Stream<core::int*>* /* originally async* */ {
     asy::_AsyncStarStreamController<core::int*>* :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -112,7 +107,6 @@ static method test() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<core::int*>(:async_op);
diff --git a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.strong.transformed.expect
index 7ef736b734c..4aa6578e67a 100644
--- a/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/infer_types_on_loop_indices_for_each_loop_async.dart.strong.transformed.expect
@@ -59,7 +59,6 @@ class Bar<T extends asy::Stream<core::String*>* = asy::Stream<core::String*>*> e
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -104,7 +103,6 @@ class Bar<T extends asy::Stream<core::String*>* = asy::Stream<core::String*>*> e
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -130,7 +128,6 @@ class Baz<T extends core::Object* = dynamic, E extends asy::Stream<self::Baz::T*
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -176,7 +173,6 @@ class Baz<T extends core::Object* = dynamic, E extends asy::Stream<self::Baz::T*
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -249,7 +245,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -451,7 +446,6 @@ Try changing the type of the variable.
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference/local_return_and_yield.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/local_return_and_yield.dart.strong.transformed.expect
index 273bbbec8ec..57169ca611c 100644
--- a/pkg/front_end/testcases/inference/local_return_and_yield.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/local_return_and_yield.dart.strong.transformed.expect
@@ -22,7 +22,6 @@ static method main() → dynamic {
     final asy::_Future<(core::int*) →* core::int*>* :async_future = new asy::_Future::•<(core::int*) →* core::int*>();
     core::bool* :is_sync = false;
     FutureOr<(core::int*) →* core::int*>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -43,7 +42,6 @@ static method main() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -87,7 +85,6 @@ static method main() → dynamic {
   function e() → asy::Stream<(core::int*) →* core::int*>* /* originally async* */ {
     asy::_AsyncStarStreamController<(core::int*) →* core::int*>* :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -112,7 +109,6 @@ static method main() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<(core::int*) →* core::int*>(:async_op);
@@ -122,7 +118,6 @@ static method main() → dynamic {
   function f() → asy::Stream<(core::int*) →* core::int*>* /* originally async* */ {
     asy::_AsyncStarStreamController<(core::int*) →* core::int*>* :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -147,7 +142,6 @@ static method main() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<(core::int*) →* core::int*>(:async_op);
diff --git a/pkg/front_end/testcases/inference/top_level_return_and_yield.dart.strong.transformed.expect b/pkg/front_end/testcases/inference/top_level_return_and_yield.dart.strong.transformed.expect
index 0028ef636d4..340170ef395 100644
--- a/pkg/front_end/testcases/inference/top_level_return_and_yield.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference/top_level_return_and_yield.dart.strong.transformed.expect
@@ -21,7 +21,6 @@ static method b() → asy::Future<(core::int*) →* core::int*>* /* originally a
   final asy::_Future<(core::int*) →* core::int*>* :async_future = new asy::_Future::•<(core::int*) →* core::int*>();
   core::bool* :is_sync = false;
   FutureOr<(core::int*) →* core::int*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -42,7 +41,6 @@ static method b() → asy::Future<(core::int*) →* core::int*>* /* originally a
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -86,7 +84,6 @@ static method d() → core::Iterable<(core::int*) →* core::int*>* /* originall
 static method e() → asy::Stream<(core::int*) →* core::int*>* /* originally async* */ {
   asy::_AsyncStarStreamController<(core::int*) →* core::int*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -111,7 +108,6 @@ static method e() → asy::Stream<(core::int*) →* core::int*>* /* originally a
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<(core::int*) →* core::int*>(:async_op);
@@ -121,7 +117,6 @@ static method e() → asy::Stream<(core::int*) →* core::int*>* /* originally a
 static method f() → asy::Stream<(core::int*) →* core::int*>* /* originally async* */ {
   asy::_AsyncStarStreamController<(core::int*) →* core::int*>* :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -146,7 +141,6 @@ static method f() → asy::Stream<(core::int*) →* core::int*>* /* originally a
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<(core::int*) →* core::int*>(:async_op);
diff --git a/pkg/front_end/testcases/inference_new/for_each_invalid_iterable.dart.strong.transformed.expect b/pkg/front_end/testcases/inference_new/for_each_invalid_iterable.dart.strong.transformed.expect
index 1af0a51710a..75740f52f3a 100644
--- a/pkg/front_end/testcases/inference_new/for_each_invalid_iterable.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference_new/for_each_invalid_iterable.dart.strong.transformed.expect
@@ -31,7 +31,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -129,7 +128,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/inference_new/for_each_outer_var_type.dart.strong.transformed.expect b/pkg/front_end/testcases/inference_new/for_each_outer_var_type.dart.strong.transformed.expect
index 0d9cdbd1181..c9f269d3cb6 100644
--- a/pkg/front_end/testcases/inference_new/for_each_outer_var_type.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/inference_new/for_each_outer_var_type.dart.strong.transformed.expect
@@ -47,7 +47,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -208,7 +207,6 @@ Try changing the type of the variable.
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/late_lowering/later.dart.strong.transformed.expect b/pkg/front_end/testcases/late_lowering/later.dart.strong.transformed.expect
index d9e572e865a..0ac77b21b22 100644
--- a/pkg/front_end/testcases/late_lowering/later.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/late_lowering/later.dart.strong.transformed.expect
@@ -140,7 +140,6 @@ static method hest() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -185,7 +184,6 @@ static method hest() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -196,7 +194,6 @@ static method fisk() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -225,7 +222,6 @@ static method fisk() → dynamic /* originally async */ {
             final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
             core::bool* :is_sync = false;
             FutureOr<dynamic>? :return_value;
-            dynamic :async_stack_trace;
             (dynamic) → dynamic :async_op_then;
             (core::Object, core::StackTrace) → dynamic :async_op_error;
             core::int :await_jump_var = 0;
@@ -245,7 +241,6 @@ static method fisk() → dynamic /* originally async */ {
               on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
                 asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
               }
-            :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
             :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
             :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
             :async_op.call();
@@ -261,7 +256,6 @@ static method fisk() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -276,4 +270,4 @@ constants  {
 
 Extra constant evaluation status:
 Evaluated: VariableGet @ org-dartlang-testcase:///later.dart:46:18 -> IntConstant(42)
-Extra constant evaluation: evaluated: 216, effectively constant: 1
+Extra constant evaluation: evaluated: 207, effectively constant: 1
diff --git a/pkg/front_end/testcases/late_lowering/later.dart.weak.transformed.expect b/pkg/front_end/testcases/late_lowering/later.dart.weak.transformed.expect
index abfa48e1701..ffd2c5bec40 100644
--- a/pkg/front_end/testcases/late_lowering/later.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/late_lowering/later.dart.weak.transformed.expect
@@ -160,7 +160,6 @@ static method hest() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -205,7 +204,6 @@ static method hest() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -216,7 +214,6 @@ static method fisk() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -263,7 +260,6 @@ static method fisk() → dynamic /* originally async */ {
               final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
               core::bool* :is_sync = false;
               FutureOr<dynamic>? :return_value;
-              dynamic :async_stack_trace;
               (dynamic) → dynamic :async_op_then;
               (core::Object, core::StackTrace) → dynamic :async_op_error;
               core::int :await_jump_var = 0;
@@ -283,7 +279,6 @@ static method fisk() → dynamic /* originally async */ {
                 on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
                   asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
                 }
-              :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
               :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
               :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
               :async_op.call();
@@ -305,7 +300,6 @@ static method fisk() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.strong.transformed.expect
index 2c1bc3e76d5..d02c7bcaa2a 100644
--- a/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.strong.transformed.expect
@@ -276,7 +276,6 @@ Try changing the type of the variable.
     final asy::_Future<self::A> :async_future = new asy::_Future::•<self::A>();
     core::bool* :is_sync = false;
     FutureOr<self::A>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -309,7 +308,6 @@ Try changing the type of the variable.
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -412,7 +410,6 @@ static method boz(Null x) → self::A {
     final asy::_Future<self::A> :async_future = new asy::_Future::•<self::A>();
     core::bool* :is_sync = false;
     FutureOr<self::A>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -443,7 +440,6 @@ static method boz(Null x) → self::A {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -470,4 +466,4 @@ Evaluated: VariableGet @ org-dartlang-testcase:///assignability_error_messages.d
 Evaluated: MethodInvocation @ org-dartlang-testcase:///assignability_error_messages.dart:77:14 -> BoolConstant(true)
 Evaluated: VariableGet @ org-dartlang-testcase:///assignability_error_messages.dart:77:14 -> NullConstant(null)
 Evaluated: VariableGet @ org-dartlang-testcase:///assignability_error_messages.dart:77:14 -> NullConstant(null)
-Extra constant evaluation: evaluated: 216, effectively constant: 12
+Extra constant evaluation: evaluated: 210, effectively constant: 12
diff --git a/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.weak.transformed.expect
index a63f3a479c5..9ec61e26f89 100644
--- a/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/assignability_error_messages.dart.weak.transformed.expect
@@ -276,7 +276,6 @@ Try changing the type of the variable.
     final asy::_Future<self::A> :async_future = new asy::_Future::•<self::A>();
     core::bool* :is_sync = false;
     FutureOr<self::A>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -309,7 +308,6 @@ Try changing the type of the variable.
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -412,7 +410,6 @@ static method boz(Null x) → self::A {
     final asy::_Future<self::A> :async_future = new asy::_Future::•<self::A>();
     core::bool* :is_sync = false;
     FutureOr<self::A>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -443,7 +440,6 @@ static method boz(Null x) → self::A {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.strong.transformed.expect
index cfe4af385a7..c6344c12815 100644
--- a/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.strong.transformed.expect
@@ -9,7 +9,6 @@ abstract class TestMixin<R extends core::Object? = dynamic, T extends core::Obje
     final asy::_Future<self::TestMixin::T%> :async_future = new asy::_Future::•<self::TestMixin::T%>();
     core::bool* :is_sync = false;
     FutureOr<self::TestMixin::T%>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -45,7 +44,6 @@ abstract class TestMixin<R extends core::Object? = dynamic, T extends core::Obje
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -79,7 +77,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
     core::bool* :is_sync = false;
     FutureOr<core::String>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -115,7 +112,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -140,7 +136,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
     core::bool* :is_sync = false;
     FutureOr<core::String>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -176,7 +171,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.weak.transformed.expect
index cfe4af385a7..c6344c12815 100644
--- a/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/flutter_issue64155.dart.weak.transformed.expect
@@ -9,7 +9,6 @@ abstract class TestMixin<R extends core::Object? = dynamic, T extends core::Obje
     final asy::_Future<self::TestMixin::T%> :async_future = new asy::_Future::•<self::TestMixin::T%>();
     core::bool* :is_sync = false;
     FutureOr<self::TestMixin::T%>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -45,7 +44,6 @@ abstract class TestMixin<R extends core::Object? = dynamic, T extends core::Obje
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -79,7 +77,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
     core::bool* :is_sync = false;
     FutureOr<core::String>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -115,7 +112,6 @@ abstract class _Class1&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -140,7 +136,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
     final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
     core::bool* :is_sync = false;
     FutureOr<core::String>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -176,7 +171,6 @@ abstract class _Class2&Object&TestMixin extends core::Object implements self::Te
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41108.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41108.dart.strong.transformed.expect
index 50e24cb4a5f..eddf0ffd221 100644
--- a/pkg/front_end/testcases/nnbd/issue41108.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41108.dart.strong.transformed.expect
@@ -16,7 +16,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -39,7 +38,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41108.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41108.dart.weak.transformed.expect
index 8631965a829..af2456089b5 100644
--- a/pkg/front_end/testcases/nnbd/issue41108.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41108.dart.weak.transformed.expect
@@ -16,7 +16,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -39,7 +38,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41114.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41114.dart.strong.transformed.expect
index 0d0a5f6dac6..5f03cd5edec 100644
--- a/pkg/front_end/testcases/nnbd/issue41114.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41114.dart.strong.transformed.expect
@@ -7,7 +7,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -27,7 +26,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41114.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41114.dart.weak.transformed.expect
index 0d0a5f6dac6..5f03cd5edec 100644
--- a/pkg/front_end/testcases/nnbd/issue41114.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41114.dart.weak.transformed.expect
@@ -7,7 +7,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -27,7 +26,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41156.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41156.dart.strong.transformed.expect
index 2d5c92d13d4..3e9bef1287e 100644
--- a/pkg/front_end/testcases/nnbd/issue41156.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41156.dart.strong.transformed.expect
@@ -59,7 +59,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -77,7 +76,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -88,7 +86,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -105,7 +102,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -116,7 +112,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -134,7 +129,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -145,7 +139,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -163,7 +156,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -174,7 +166,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -191,7 +182,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -202,7 +192,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -220,7 +209,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -232,7 +220,6 @@ static method errors() → void /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -285,7 +272,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -310,7 +296,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -321,7 +306,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -347,7 +331,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -358,7 +341,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -383,7 +365,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -394,7 +375,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -420,7 +400,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -434,7 +413,6 @@ static method errors() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41156.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41156.dart.weak.transformed.expect
index f6571573937..e3ff8f7f007 100644
--- a/pkg/front_end/testcases/nnbd/issue41156.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41156.dart.weak.transformed.expect
@@ -60,7 +60,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -78,7 +77,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -89,7 +87,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -106,7 +103,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -117,7 +113,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -135,7 +130,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -146,7 +140,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -164,7 +157,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -175,7 +167,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -192,7 +183,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -203,7 +193,6 @@ static method main() → void {
     final asy::_Future<Never> :async_future = new asy::_Future::•<Never>();
     core::bool* :is_sync = false;
     FutureOr<Never>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -221,7 +210,6 @@ static method main() → void {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -233,7 +221,6 @@ static method errors() → void /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -286,7 +273,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -311,7 +297,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -322,7 +307,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -348,7 +332,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -359,7 +342,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -384,7 +366,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -395,7 +376,6 @@ static method errors() → void /* originally async */ {
           final asy::_Future<core::String> :async_future = new asy::_Future::•<core::String>();
           core::bool* :is_sync = false;
           FutureOr<core::String>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -421,7 +401,6 @@ static method errors() → void /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -435,7 +414,6 @@ static method errors() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437a.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437a.dart.strong.transformed.expect
index 049ebe600ae..b4ab7d24ae6 100644
--- a/pkg/front_end/testcases/nnbd/issue41437a.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437a.dart.strong.transformed.expect
@@ -37,7 +37,6 @@ static method getFutureNull() → asy::Future<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -55,7 +54,6 @@ static method getFutureNull() → asy::Future<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -66,7 +64,6 @@ static method getFutureBool() → asy::Future<core::bool> /* originally async */
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -84,7 +81,6 @@ static method getFutureBool() → asy::Future<core::bool> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -95,7 +91,6 @@ static method test1() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -115,7 +110,6 @@ static method test1() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -130,7 +124,6 @@ static method test4() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -150,7 +143,6 @@ static method test4() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -168,7 +160,6 @@ static method test7() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -186,7 +177,6 @@ static method test7() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -197,7 +187,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -230,7 +218,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -245,7 +232,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -265,7 +251,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -283,7 +268,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -301,7 +285,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -315,7 +298,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
           core::bool* :is_sync = false;
           FutureOr<dynamic>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -335,7 +317,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -351,7 +332,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
           core::bool* :is_sync = false;
           FutureOr<dynamic>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -371,7 +351,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -387,7 +366,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -405,7 +383,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -419,7 +396,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437a.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437a.dart.weak.transformed.expect
index 049ebe600ae..b4ab7d24ae6 100644
--- a/pkg/front_end/testcases/nnbd/issue41437a.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437a.dart.weak.transformed.expect
@@ -37,7 +37,6 @@ static method getFutureNull() → asy::Future<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -55,7 +54,6 @@ static method getFutureNull() → asy::Future<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -66,7 +64,6 @@ static method getFutureBool() → asy::Future<core::bool> /* originally async */
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -84,7 +81,6 @@ static method getFutureBool() → asy::Future<core::bool> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -95,7 +91,6 @@ static method test1() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -115,7 +110,6 @@ static method test1() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -130,7 +124,6 @@ static method test4() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -150,7 +143,6 @@ static method test4() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -168,7 +160,6 @@ static method test7() → asy::Future<core::bool> /* originally async */ {
   final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
   core::bool* :is_sync = false;
   FutureOr<core::bool>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -186,7 +177,6 @@ static method test7() → asy::Future<core::bool> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -197,7 +187,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -210,7 +199,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -230,7 +218,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -245,7 +232,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -265,7 +251,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -283,7 +268,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -301,7 +285,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -315,7 +298,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
           core::bool* :is_sync = false;
           FutureOr<dynamic>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -335,7 +317,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -351,7 +332,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
           core::bool* :is_sync = false;
           FutureOr<dynamic>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -371,7 +351,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -387,7 +366,6 @@ static method test() → dynamic /* originally async */ {
           final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
           core::bool* :is_sync = false;
           FutureOr<core::bool>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -405,7 +383,6 @@ static method test() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -419,7 +396,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437b.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437b.dart.strong.transformed.expect
index fb81d0db69e..1cc9b7b8dc9 100644
--- a/pkg/front_end/testcases/nnbd/issue41437b.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437b.dart.strong.transformed.expect
@@ -146,7 +146,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -291,7 +290,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437b.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437b.dart.weak.transformed.expect
index fb81d0db69e..1cc9b7b8dc9 100644
--- a/pkg/front_end/testcases/nnbd/issue41437b.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437b.dart.weak.transformed.expect
@@ -146,7 +146,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -291,7 +290,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437c.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437c.dart.strong.transformed.expect
index 5bfffb30521..6fa863c3fc9 100644
--- a/pkg/front_end/testcases/nnbd/issue41437c.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437c.dart.strong.transformed.expect
@@ -46,7 +46,6 @@ static method getNull() → dynamic
 static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -71,7 +70,6 @@ static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -81,7 +79,6 @@ static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
 static method getStreamBool() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -106,7 +103,6 @@ static method getStreamBool() → asy::Stream<core::bool> /* originally async* *
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -116,7 +112,6 @@ static method getStreamBool() → asy::Stream<core::bool> /* originally async* *
 static method test1() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -141,7 +136,6 @@ static method test1() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -155,7 +149,6 @@ static method test3() → core::bool
 static method test4() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -183,7 +176,6 @@ static method test4() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -200,7 +192,6 @@ static method test6() → asy::Stream<core::bool>
 static method test7() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -225,7 +216,6 @@ static method test7() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -236,7 +226,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -248,7 +237,6 @@ static method test() → dynamic /* originally async */ {
         function test1() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -273,7 +261,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -287,7 +274,6 @@ static method test() → dynamic /* originally async */ {
         function test4() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -315,7 +301,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -332,7 +317,6 @@ static method test() → dynamic /* originally async */ {
         function test7() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -357,7 +341,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -370,7 +353,6 @@ static method test() → dynamic /* originally async */ {
     ^" in (() → asy::Stream<dynamic> /* originally async* */ {
           asy::_AsyncStarStreamController<dynamic>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -395,7 +377,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -410,7 +391,6 @@ static method test() → dynamic /* originally async */ {
     ^" in (() → asy::Stream<dynamic> /* originally async* */ {
           asy::_AsyncStarStreamController<dynamic>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -435,7 +415,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -450,7 +429,6 @@ static method test() → dynamic /* originally async */ {
         asy::Stream<core::bool> var7 = (() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -475,7 +453,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -489,7 +466,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41437c.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41437c.dart.weak.transformed.expect
index 5bfffb30521..6fa863c3fc9 100644
--- a/pkg/front_end/testcases/nnbd/issue41437c.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41437c.dart.weak.transformed.expect
@@ -46,7 +46,6 @@ static method getNull() → dynamic
 static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -71,7 +70,6 @@ static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -81,7 +79,6 @@ static method getStreamNull() → asy::Stream<dynamic> /* originally async* */ {
 static method getStreamBool() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -106,7 +103,6 @@ static method getStreamBool() → asy::Stream<core::bool> /* originally async* *
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -116,7 +112,6 @@ static method getStreamBool() → asy::Stream<core::bool> /* originally async* *
 static method test1() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -141,7 +136,6 @@ static method test1() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -155,7 +149,6 @@ static method test3() → core::bool
 static method test4() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -183,7 +176,6 @@ static method test4() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -200,7 +192,6 @@ static method test6() → asy::Stream<core::bool>
 static method test7() → asy::Stream<core::bool> /* originally async* */ {
   asy::_AsyncStarStreamController<core::bool>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -225,7 +216,6 @@ static method test7() → asy::Stream<core::bool> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -236,7 +226,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -248,7 +237,6 @@ static method test() → dynamic /* originally async */ {
         function test1() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -273,7 +261,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -287,7 +274,6 @@ static method test() → dynamic /* originally async */ {
         function test4() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -315,7 +301,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -332,7 +317,6 @@ static method test() → dynamic /* originally async */ {
         function test7() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -357,7 +341,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -370,7 +353,6 @@ static method test() → dynamic /* originally async */ {
     ^" in (() → asy::Stream<dynamic> /* originally async* */ {
           asy::_AsyncStarStreamController<dynamic>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -395,7 +377,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -410,7 +391,6 @@ static method test() → dynamic /* originally async */ {
     ^" in (() → asy::Stream<dynamic> /* originally async* */ {
           asy::_AsyncStarStreamController<dynamic>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -435,7 +415,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -450,7 +429,6 @@ static method test() → dynamic /* originally async */ {
         asy::Stream<core::bool> var7 = (() → asy::Stream<core::bool> /* originally async* */ {
           asy::_AsyncStarStreamController<core::bool>? :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -475,7 +453,6 @@ static method test() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<core::bool>(:async_op);
@@ -489,7 +466,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41602.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41602.dart.strong.transformed.expect
index 1add5c80dd1..e85bc0e0b54 100644
--- a/pkg/front_end/testcases/nnbd/issue41602.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41602.dart.strong.transformed.expect
@@ -19,7 +19,6 @@ static method returnFutureOfVoid() → asy::Future<void> /* originally async */
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -34,7 +33,6 @@ static method returnFutureOfVoid() → asy::Future<void> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -46,7 +44,6 @@ static method returnVoidAsync() → void /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -61,7 +58,6 @@ static method returnVoidAsync() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -72,7 +68,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -93,7 +88,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -104,7 +98,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -123,7 +116,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41602.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41602.dart.weak.transformed.expect
index 1add5c80dd1..e85bc0e0b54 100644
--- a/pkg/front_end/testcases/nnbd/issue41602.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41602.dart.weak.transformed.expect
@@ -19,7 +19,6 @@ static method returnFutureOfVoid() → asy::Future<void> /* originally async */
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -34,7 +33,6 @@ static method returnFutureOfVoid() → asy::Future<void> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -46,7 +44,6 @@ static method returnVoidAsync() → void /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -61,7 +58,6 @@ static method returnVoidAsync() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -72,7 +68,6 @@ static method test() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -93,7 +88,6 @@ static method test() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -104,7 +98,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -123,7 +116,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
index af60f0bdd76..b287a579483 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.strong.transformed.expect
@@ -38,7 +38,6 @@ static method test1(self::C<core::num> c) → dynamic {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -58,7 +57,6 @@ static method test1(self::C<core::num> c) → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -76,7 +74,6 @@ static method test2(self::C<core::num?> c) → dynamic {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -99,7 +96,6 @@ static method test2(self::C<core::num?> c) → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
index af60f0bdd76..b287a579483 100644
--- a/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue41697.dart.weak.transformed.expect
@@ -38,7 +38,6 @@ static method test1(self::C<core::num> c) → dynamic {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -58,7 +57,6 @@ static method test1(self::C<core::num> c) → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -76,7 +74,6 @@ static method test2(self::C<core::num?> c) → dynamic {
     final asy::_Future<core::num> :async_future = new asy::_Future::•<core::num>();
     core::bool* :is_sync = false;
     FutureOr<core::num>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -99,7 +96,6 @@ static method test2(self::C<core::num?> c) → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue42540.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue42540.dart.strong.transformed.expect
index 630569b2b72..4e127a62a70 100644
--- a/pkg/front_end/testcases/nnbd/issue42540.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42540.dart.strong.transformed.expect
@@ -9,7 +9,6 @@ static method fn() → asy::Future<core::Object> /* originally async */ {
   final asy::_Future<core::Object> :async_future = new asy::_Future::•<core::Object>();
   core::bool* :is_sync = false;
   FutureOr<core::Object>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method fn() → asy::Future<core::Object> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue42540.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue42540.dart.weak.transformed.expect
index d317b87bb63..e61b30d49c0 100644
--- a/pkg/front_end/testcases/nnbd/issue42540.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42540.dart.weak.transformed.expect
@@ -9,7 +9,6 @@ static method fn() → asy::Future<core::Object> /* originally async */ {
   final asy::_Future<core::Object> :async_future = new asy::_Future::•<core::Object>();
   core::bool* :is_sync = false;
   FutureOr<core::Object>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -31,7 +30,6 @@ static method fn() → asy::Future<core::Object> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue42743.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/issue42743.dart.strong.transformed.expect
index 47601b20253..e489262b240 100644
--- a/pkg/front_end/testcases/nnbd/issue42743.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42743.dart.strong.transformed.expect
@@ -7,7 +7,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -25,7 +24,6 @@ static method main() → dynamic /* originally async */ {
           final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
           core::bool* :is_sync = false;
           FutureOr<core::int?>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -45,7 +43,6 @@ static method main() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -59,7 +56,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/issue42743.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/issue42743.dart.weak.transformed.expect
index 47601b20253..e489262b240 100644
--- a/pkg/front_end/testcases/nnbd/issue42743.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/issue42743.dart.weak.transformed.expect
@@ -7,7 +7,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -25,7 +24,6 @@ static method main() → dynamic /* originally async */ {
           final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
           core::bool* :is_sync = false;
           FutureOr<core::int?>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -45,7 +43,6 @@ static method main() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -59,7 +56,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/later.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/later.dart.strong.transformed.expect
index 25b17c93855..c198bf370d5 100644
--- a/pkg/front_end/testcases/nnbd/later.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/later.dart.strong.transformed.expect
@@ -127,7 +127,6 @@ static method hest() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -172,7 +171,6 @@ static method hest() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -183,7 +181,6 @@ static method fisk() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -207,7 +204,6 @@ static method fisk() → dynamic /* originally async */ {
             final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
             core::bool* :is_sync = false;
             FutureOr<dynamic>? :return_value;
-            dynamic :async_stack_trace;
             (dynamic) → dynamic :async_op_then;
             (core::Object, core::StackTrace) → dynamic :async_op_error;
             core::int :await_jump_var = 0;
@@ -227,7 +223,6 @@ static method fisk() → dynamic /* originally async */ {
               on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
                 asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
               }
-            :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
             :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
             :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
             :async_op.call();
@@ -242,7 +237,6 @@ static method fisk() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/later.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/later.dart.weak.transformed.expect
index 25b17c93855..c198bf370d5 100644
--- a/pkg/front_end/testcases/nnbd/later.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/later.dart.weak.transformed.expect
@@ -127,7 +127,6 @@ static method hest() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -172,7 +171,6 @@ static method hest() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -183,7 +181,6 @@ static method fisk() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -207,7 +204,6 @@ static method fisk() → dynamic /* originally async */ {
             final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
             core::bool* :is_sync = false;
             FutureOr<dynamic>? :return_value;
-            dynamic :async_stack_trace;
             (dynamic) → dynamic :async_op_then;
             (core::Object, core::StackTrace) → dynamic :async_op_error;
             core::int :await_jump_var = 0;
@@ -227,7 +223,6 @@ static method fisk() → dynamic /* originally async */ {
               on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
                 asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
               }
-            :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
             :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
             :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
             :async_op.call();
@@ -242,7 +237,6 @@ static method fisk() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/return_async.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/return_async.dart.strong.transformed.expect
index 8c64d783bfc..b9094ae2687 100644
--- a/pkg/front_end/testcases/nnbd/return_async.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/return_async.dart.strong.transformed.expect
@@ -13,7 +13,6 @@ static method allYield() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -34,7 +33,6 @@ static method allYield() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -45,7 +43,6 @@ static method allYield2() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -66,7 +63,6 @@ static method allYield2() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -77,7 +73,6 @@ static method allYield3() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -97,7 +92,6 @@ static method allYield3() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -108,7 +102,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -122,7 +115,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
           final asy::_Future<Null> :async_future = new asy::_Future::•<Null>();
           core::bool* :is_sync = false;
           FutureOr<Null>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -142,7 +134,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -160,7 +151,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/return_async.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/return_async.dart.weak.transformed.expect
index 8c64d783bfc..b9094ae2687 100644
--- a/pkg/front_end/testcases/nnbd/return_async.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/return_async.dart.weak.transformed.expect
@@ -13,7 +13,6 @@ static method allYield() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -34,7 +33,6 @@ static method allYield() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -45,7 +43,6 @@ static method allYield2() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -66,7 +63,6 @@ static method allYield2() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -77,7 +73,6 @@ static method allYield3() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -97,7 +92,6 @@ static method allYield3() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -108,7 +102,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
   final asy::_Future<void> :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -122,7 +115,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
           final asy::_Future<Null> :async_future = new asy::_Future::•<Null>();
           core::bool* :is_sync = false;
           FutureOr<Null>? :return_value;
-          dynamic :async_stack_trace;
           (dynamic) → dynamic :async_op_then;
           (core::Object, core::StackTrace) → dynamic :async_op_error;
           core::int :await_jump_var = 0;
@@ -142,7 +134,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -160,7 +151,6 @@ static method customErrorZone() → asy::Future<void> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/nnbd/return_null.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/return_null.dart.strong.transformed.expect
index 66eca58774c..dfdc501bf2e 100644
--- a/pkg/front_end/testcases/nnbd/return_null.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/return_null.dart.strong.transformed.expect
@@ -97,7 +97,6 @@ static method returnAsync1() → asy::Future<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -112,7 +111,6 @@ static method returnAsync1() → asy::Future<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -123,7 +121,6 @@ static method returnAsync2() → FutureOr<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -138,7 +135,6 @@ static method returnAsync2() → FutureOr<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -149,7 +145,6 @@ static method returnAsync3() → FutureOr<core::int> /* originally async */ {
   final asy::_Future<core::int> :async_future = new asy::_Future::•<core::int>();
   core::bool* :is_sync = false;
   FutureOr<core::int>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -169,7 +164,6 @@ FutureOr<int> returnAsync3() async {} // error
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -180,7 +174,6 @@ static method returnAsync4() → FutureOr<core::int?> /* originally async */ {
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -195,7 +188,6 @@ static method returnAsync4() → FutureOr<core::int?> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -206,7 +198,6 @@ static method returnAsync5() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -221,7 +212,6 @@ static method returnAsync5() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -232,7 +222,6 @@ static method returnAsync6() → asy::Future<core::int?> /* originally async */
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -250,7 +239,6 @@ static method returnAsync6() → asy::Future<core::int?> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -261,7 +249,6 @@ static method returnAsync7() → asy::Future<core::int?> /* originally async */
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -276,7 +263,6 @@ static method returnAsync7() → asy::Future<core::int?> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -298,7 +284,6 @@ static method yieldSync() → core::Iterable<dynamic> /* originally sync* */ {
 static method yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -316,7 +301,6 @@ static method yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -381,7 +365,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -396,7 +379,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -407,7 +389,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -422,7 +403,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -433,7 +413,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int> :async_future = new asy::_Future::•<core::int>();
     core::bool* :is_sync = false;
     FutureOr<core::int>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -453,7 +432,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -464,7 +442,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -479,7 +456,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -490,7 +466,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<Null> :async_future = new asy::_Future::•<Null>();
     core::bool* :is_sync = false;
     FutureOr<Null>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -505,7 +480,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -516,7 +490,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -534,7 +507,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -545,7 +517,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -560,7 +531,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -582,7 +552,6 @@ static method localFunctions() → dynamic {
   function yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
     asy::_AsyncStarStreamController<dynamic>? :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -600,7 +569,6 @@ static method localFunctions() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -674,4 +642,4 @@ Evaluated: VariableGet @ org-dartlang-testcase:///return_null.dart:69:12 -> Null
 Evaluated: MethodInvocation @ org-dartlang-testcase:///return_null.dart:75:14 -> BoolConstant(true)
 Evaluated: VariableGet @ org-dartlang-testcase:///return_null.dart:75:14 -> NullConstant(null)
 Evaluated: VariableGet @ org-dartlang-testcase:///return_null.dart:75:14 -> NullConstant(null)
-Extra constant evaluation: evaluated: 442, effectively constant: 12
+Extra constant evaluation: evaluated: 394, effectively constant: 12
diff --git a/pkg/front_end/testcases/nnbd/return_null.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/return_null.dart.weak.transformed.expect
index 4b3b79ca540..0c0ae45032e 100644
--- a/pkg/front_end/testcases/nnbd/return_null.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/return_null.dart.weak.transformed.expect
@@ -98,7 +98,6 @@ static method returnAsync1() → asy::Future<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -113,7 +112,6 @@ static method returnAsync1() → asy::Future<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -124,7 +122,6 @@ static method returnAsync2() → FutureOr<dynamic> /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -139,7 +136,6 @@ static method returnAsync2() → FutureOr<dynamic> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -150,7 +146,6 @@ static method returnAsync3() → FutureOr<core::int> /* originally async */ {
   final asy::_Future<core::int> :async_future = new asy::_Future::•<core::int>();
   core::bool* :is_sync = false;
   FutureOr<core::int>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -170,7 +165,6 @@ FutureOr<int> returnAsync3() async {} // error
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -181,7 +175,6 @@ static method returnAsync4() → FutureOr<core::int?> /* originally async */ {
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -196,7 +189,6 @@ static method returnAsync4() → FutureOr<core::int?> /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -207,7 +199,6 @@ static method returnAsync5() → dynamic /* originally async */ {
   final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -222,7 +213,6 @@ static method returnAsync5() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -233,7 +223,6 @@ static method returnAsync6() → asy::Future<core::int?> /* originally async */
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -251,7 +240,6 @@ static method returnAsync6() → asy::Future<core::int?> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -262,7 +250,6 @@ static method returnAsync7() → asy::Future<core::int?> /* originally async */
   final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
   core::bool* :is_sync = false;
   FutureOr<core::int?>? :return_value;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -277,7 +264,6 @@ static method returnAsync7() → asy::Future<core::int?> /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -299,7 +285,6 @@ static method yieldSync() → core::Iterable<dynamic> /* originally sync* */ {
 static method yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
   asy::_AsyncStarStreamController<dynamic>? :controller;
   dynamic :controller_stream;
-  dynamic :async_stack_trace;
   (dynamic) → dynamic :async_op_then;
   (core::Object, core::StackTrace) → dynamic :async_op_error;
   core::int :await_jump_var = 0;
@@ -317,7 +302,6 @@ static method yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
     finally {
       :controller.{asy::_AsyncStarStreamController::close}();
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -385,7 +369,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -400,7 +383,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -411,7 +393,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -426,7 +407,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -437,7 +417,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int> :async_future = new asy::_Future::•<core::int>();
     core::bool* :is_sync = false;
     FutureOr<core::int>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -457,7 +436,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -468,7 +446,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -483,7 +460,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -494,7 +470,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<Null> :async_future = new asy::_Future::•<Null>();
     core::bool* :is_sync = false;
     FutureOr<Null>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -509,7 +484,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -520,7 +494,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -538,7 +511,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -549,7 +521,6 @@ static method localFunctions() → dynamic {
     final asy::_Future<core::int?> :async_future = new asy::_Future::•<core::int?>();
     core::bool* :is_sync = false;
     FutureOr<core::int?>? :return_value;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -564,7 +535,6 @@ static method localFunctions() → dynamic {
       on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :async_op.call();
@@ -586,7 +556,6 @@ static method localFunctions() → dynamic {
   function yieldAsync() → asy::Stream<dynamic> /* originally async* */ {
     asy::_AsyncStarStreamController<dynamic>? :controller;
     dynamic :controller_stream;
-    dynamic :async_stack_trace;
     (dynamic) → dynamic :async_op_then;
     (core::Object, core::StackTrace) → dynamic :async_op_error;
     core::int :await_jump_var = 0;
@@ -604,7 +573,6 @@ static method localFunctions() → dynamic {
       finally {
         :controller.{asy::_AsyncStarStreamController::close}();
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
diff --git a/pkg/front_end/testcases/nnbd_mixed/issue41602.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd_mixed/issue41602.dart.weak.transformed.expect
index ee6d621c5e6..faea41fabdd 100644
--- a/pkg/front_end/testcases/nnbd_mixed/issue41602.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd_mixed/issue41602.dart.weak.transformed.expect
@@ -8,7 +8,6 @@ static method returnFutureOfVoid() → asy::Future<void>* /* originally async */
   final asy::_Future<void>* :async_future = new asy::_Future::•<void>();
   core::bool* :is_sync = false;
   FutureOr<void>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -23,7 +22,6 @@ static method returnFutureOfVoid() → asy::Future<void>* /* originally async */
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -35,7 +33,6 @@ static method returnVoidAsync() → void /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -50,7 +47,6 @@ static method returnVoidAsync() → void /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -61,7 +57,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -84,7 +79,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/regress/issue_34850.dart.strong.transformed.expect b/pkg/front_end/testcases/regress/issue_34850.dart.strong.transformed.expect
index 15f42cb96a9..5b90ebe4c89 100644
--- a/pkg/front_end/testcases/regress/issue_34850.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/regress/issue_34850.dart.strong.transformed.expect
@@ -63,7 +63,6 @@ static method f2() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -81,7 +80,6 @@ static method f2() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -92,7 +90,6 @@ static method f3() → invalid-type /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -110,7 +107,6 @@ static method f3() → invalid-type /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -121,7 +117,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -143,7 +138,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/regress/issue_37681.dart.strong.transformed.expect b/pkg/front_end/testcases/regress/issue_37681.dart.strong.transformed.expect
index a16254cd824..8458a5780b6 100644
--- a/pkg/front_end/testcases/regress/issue_37681.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/regress/issue_37681.dart.strong.transformed.expect
@@ -23,7 +23,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -40,7 +39,6 @@ static method main() → dynamic /* originally async */ {
           final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
           core::bool* :is_sync = false;
           FutureOr<dynamic>* :return_value;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -58,7 +56,6 @@ static method main() → dynamic /* originally async */ {
             on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
               asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :async_op.call();
@@ -70,7 +67,6 @@ static method main() → dynamic /* originally async */ {
         function f_async_star() → core::int* /* originally async* */ {
           asy::_AsyncStarStreamController<dynamic>* :controller;
           dynamic :controller_stream;
-          dynamic :async_stack_trace;
           (dynamic) →* dynamic :async_op_then;
           (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
           core::int* :await_jump_var = 0;
@@ -95,7 +91,6 @@ static method main() → dynamic /* originally async */ {
             finally {
               :controller.{asy::_AsyncStarStreamController::close}();
             }
-          :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
           :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
           :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
           :controller = new asy::_AsyncStarStreamController::•<dynamic>(:async_op);
@@ -158,7 +153,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/front_end/testcases/set_literals/disambiguation_rule.dart.strong.transformed.expect b/pkg/front_end/testcases/set_literals/disambiguation_rule.dart.strong.transformed.expect
index 01725ee142f..8e38e874ebd 100644
--- a/pkg/front_end/testcases/set_literals/disambiguation_rule.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/set_literals/disambiguation_rule.dart.strong.transformed.expect
@@ -57,7 +57,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -115,7 +114,6 @@ Change the type of the map literal or the context in which it is used.
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -126,7 +124,6 @@ static method mapfun() → asy::Future<core::Map<core::int*, core::bool*>*>* /*
   final asy::_Future<core::Map<core::int*, core::bool*>*>* :async_future = new asy::_Future::•<core::Map<core::int*, core::bool*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::Map<core::int*, core::bool*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -144,7 +141,6 @@ static method mapfun() → asy::Future<core::Map<core::int*, core::bool*>*>* /*
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -155,7 +151,6 @@ static method setfun() → asy::Future<core::Set<core::int*>*>* /* originally as
   final asy::_Future<core::Set<core::int*>*>* :async_future = new asy::_Future::•<core::Set<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::Set<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -175,7 +170,6 @@ static method setfun() → asy::Future<core::Set<core::int*>*>* /* originally as
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -186,7 +180,6 @@ static method iterablefun() → asy::Future<core::Iterable<core::int*>*>* /* ori
   final asy::_Future<core::Iterable<core::int*>*>* :async_future = new asy::_Future::•<core::Iterable<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<core::Iterable<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -206,7 +199,6 @@ static method iterablefun() → asy::Future<core::Iterable<core::int*>*>* /* ori
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -217,7 +209,6 @@ static method lhsfun() → asy::Future<col::LinkedHashSet<core::int*>*>* /* orig
   final asy::_Future<col::LinkedHashSet<core::int*>*>* :async_future = new asy::_Future::•<col::LinkedHashSet<core::int*>*>();
   core::bool* :is_sync = false;
   FutureOr<col::LinkedHashSet<core::int*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -243,7 +234,6 @@ Future<LinkedHashSet<int>> lhsfun() async => {};
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
@@ -254,7 +244,6 @@ static method lhmfun() → asy::Future<col::LinkedHashMap<core::int*, core::bool
   final asy::_Future<col::LinkedHashMap<core::int*, core::bool*>*>* :async_future = new asy::_Future::•<col::LinkedHashMap<core::int*, core::bool*>*>();
   core::bool* :is_sync = false;
   FutureOr<col::LinkedHashMap<core::int*, core::bool*>*>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -278,7 +267,6 @@ Future<LinkedHashMap<int, bool>> lhmfun() async => {};
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   :async_op.call();
diff --git a/pkg/kernel/lib/core_types.dart b/pkg/kernel/lib/core_types.dart
index 24f02506275..8dadff5254e 100644
--- a/pkg/kernel/lib/core_types.dart
+++ b/pkg/kernel/lib/core_types.dart
@@ -90,7 +90,6 @@ class CoreTypes {
   Constructor _streamIteratorDefaultConstructor;
   Constructor _asyncStarStreamControllerDefaultConstructor;
   Procedure _asyncStarMoveNextHelperProcedure;
-  Procedure _asyncStackTraceHelperProcedure;
   Procedure _asyncThenWrapperHelperProcedure;
   Procedure _asyncErrorWrapperHelperProcedure;
   Procedure _awaitHelperProcedure;
@@ -233,11 +232,6 @@ class CoreTypes {
         index.getTopLevelMember('dart:async', '_asyncStarMoveNextHelper');
   }
 
-  Procedure get asyncStackTraceHelperProcedure {
-    return _asyncStackTraceHelperProcedure ??=
-        index.getTopLevelMember('dart:async', '_asyncStackTraceHelper');
-  }
-
   Procedure get asyncThenWrapperHelperProcedure {
     return _asyncThenWrapperHelperProcedure ??=
         index.getTopLevelMember('dart:async', '_asyncThenWrapperHelper');
diff --git a/pkg/kernel/lib/transformations/continuation.dart b/pkg/kernel/lib/transformations/continuation.dart
index adcb888aba6..67dcc59eaa1 100644
--- a/pkg/kernel/lib/transformations/continuation.dart
+++ b/pkg/kernel/lib/transformations/continuation.dart
@@ -22,7 +22,6 @@ class ContinuationVariables {
   static const asyncOp = ':async_op';
   static const asyncOpThen = ':async_op_then';
   static const asyncOpError = ':async_op_error';
-  static const asyncStackTraceVar = ':async_stack_trace';
   static const controller = ':controller';
   static const controllerStreamVar = ':controller_stream';
   static const forIterator = ':for-iterator';
@@ -524,8 +523,6 @@ class SyncStarFunctionRewriter extends ContinuationRewriterBase {
 }
 
 abstract class AsyncRewriterBase extends ContinuationRewriterBase {
-  final VariableDeclaration stackTraceVariable;
-
   // :async_op has type ([dynamic result, dynamic e, StackTrace? s]) -> dynamic
   final VariableDeclaration nestedClosureVariable;
 
@@ -541,9 +538,7 @@ abstract class AsyncRewriterBase extends ContinuationRewriterBase {
 
   AsyncRewriterBase(HelperNodes helper, FunctionNode enclosingFunction,
       StaticTypeContext staticTypeContext)
-      : stackTraceVariable =
-            VariableDeclaration(ContinuationVariables.asyncStackTraceVar),
-        nestedClosureVariable = VariableDeclaration(
+      : nestedClosureVariable = VariableDeclaration(
             ContinuationVariables.asyncOp,
             type: FunctionType([
               const DynamicType(),
@@ -567,9 +562,6 @@ abstract class AsyncRewriterBase extends ContinuationRewriterBase {
   void setupAsyncContinuations(List<Statement> statements) {
     expressionRewriter = new ExpressionLifter(this);
 
-    // var :async_stack_trace;
-    statements.add(stackTraceVariable);
-
     // var :async_op_then;
     statements.add(thenContinuationVariable);
 
@@ -609,13 +601,6 @@ abstract class AsyncRewriterBase extends ContinuationRewriterBase {
           ..fileOffset = enclosingFunction.parent.fileOffset;
     statements.add(closureFunction);
 
-    // :async_stack_trace = _asyncStackTraceHelper(asyncBody);
-    final stackTrace = new StaticInvocation(helper.asyncStackTraceHelper,
-        new Arguments(<Expression>[new VariableGet(nestedClosureVariable)]));
-    final stackTraceAssign = new ExpressionStatement(
-        new VariableSet(stackTraceVariable, stackTrace));
-    statements.add(stackTraceAssign);
-
     // :async_op_then = _asyncThenWrapperHelper(asyncBody);
     final boundThenClosure = new StaticInvocation(helper.asyncThenWrapper,
         new Arguments(<Expression>[new VariableGet(nestedClosureVariable)]));
@@ -1404,7 +1389,6 @@ class AsyncFunctionRewriter extends AsyncRewriterBase {
 class HelperNodes {
   final Procedure asyncErrorWrapper;
   final Library asyncLibrary;
-  final Procedure asyncStackTraceHelper;
   final Member asyncStarStreamControllerAdd;
   final Member asyncStarStreamControllerAddError;
   final Member asyncStarStreamControllerAddStream;
@@ -1442,7 +1426,6 @@ class HelperNodes {
   HelperNodes._(
       this.asyncErrorWrapper,
       this.asyncLibrary,
-      this.asyncStackTraceHelper,
       this.asyncStarStreamControllerAdd,
       this.asyncStarStreamControllerAddError,
       this.asyncStarStreamControllerAddStream,
@@ -1480,7 +1463,6 @@ class HelperNodes {
     return new HelperNodes._(
         coreTypes.asyncErrorWrapperHelperProcedure,
         coreTypes.asyncLibrary,
-        coreTypes.asyncStackTraceHelperProcedure,
         coreTypes.asyncStarStreamControllerAdd,
         coreTypes.asyncStarStreamControllerAddError,
         coreTypes.asyncStarStreamControllerAddStream,
diff --git a/pkg/test_runner/lib/src/compiler_configuration.dart b/pkg/test_runner/lib/src/compiler_configuration.dart
index 6ea866c300f..d92797d82f0 100644
--- a/pkg/test_runner/lib/src/compiler_configuration.dart
+++ b/pkg/test_runner/lib/src/compiler_configuration.dart
@@ -1085,8 +1085,6 @@ class SpecParserCompilerConfiguration extends CompilerConfiguration {
 }
 
 abstract class VMKernelCompilerMixin {
-  static final causalAsyncStacksRegExp = RegExp('--causal[_-]async[_-]stacks');
-
   TestConfiguration get _configuration;
 
   bool get _useSdk;
@@ -1116,8 +1114,6 @@ abstract class VMKernelCompilerMixin {
 
     var isProductMode = _configuration.configuration.mode == Mode.product;
 
-    var causalAsyncStacks = arguments.any(causalAsyncStacksRegExp.hasMatch);
-
     var args = [
       _isAot ? '--aot' : '--no-aot',
       '--platform=$vmPlatform',
@@ -1129,7 +1125,6 @@ abstract class VMKernelCompilerMixin {
           name.startsWith('--packages=') ||
           name.startsWith('--enable-experiment=')),
       '-Ddart.vm.product=$isProductMode',
-      '-Ddart.developer.causal_async_stacks=$causalAsyncStacks',
       if (_enableAsserts ||
           arguments.contains('--enable-asserts') ||
           arguments.contains('--enable_asserts'))
diff --git a/pkg/vm/lib/target/vm.dart b/pkg/vm/lib/target/vm.dart
index c5c5f570543..c117efac55c 100644
--- a/pkg/vm/lib/target/vm.dart
+++ b/pkg/vm/lib/target/vm.dart
@@ -464,9 +464,6 @@ class VmTarget extends Target {
     // TODO(alexmarkov): Call this from the front-end in order to have
     //  the same defines when compiling platform.
     assert(map != null);
-    if (map['dart.vm.product'] == 'true') {
-      map['dart.developer.causal_async_stacks'] = 'false';
-    }
     map['dart.isVM'] = 'true';
     // TODO(dartbug.com/36460): Derive dart.library.* definitions from platform.
     for (String library in extraRequiredLibraries) {
diff --git a/pkg/vm/testcases/transformations/deferred_loading/main.dart.expect b/pkg/vm/testcases/transformations/deferred_loading/main.dart.expect
index 7c07613761f..7d95c30ca82 100644
--- a/pkg/vm/testcases/transformations/deferred_loading/main.dart.expect
+++ b/pkg/vm/testcases/transformations/deferred_loading/main.dart.expect
@@ -49,7 +49,6 @@ LoadingUnit(id=6, parent=5,
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -66,7 +65,6 @@ LoadingUnit(id=6, parent=5,
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -82,7 +80,6 @@ library h from "#pkg/vm/testcases/transformations/deferred_loading/h.dart" as h
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -99,7 +96,6 @@ library h from "#pkg/vm/testcases/transformations/deferred_loading/h.dart" as h
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -116,7 +112,6 @@ library i from "#pkg/vm/testcases/transformations/deferred_loading/i.dart" as i
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -138,7 +133,6 @@ library i from "#pkg/vm/testcases/transformations/deferred_loading/i.dart" as i
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -154,7 +148,6 @@ library g from "#pkg/vm/testcases/transformations/deferred_loading/g.dart" as g
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -171,7 +164,6 @@ library g from "#pkg/vm/testcases/transformations/deferred_loading/g.dart" as g
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -188,7 +180,6 @@ library f from "#pkg/vm/testcases/transformations/deferred_loading/f.dart" as f
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -214,7 +205,6 @@ library f from "#pkg/vm/testcases/transformations/deferred_loading/f.dart" as f
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -230,7 +220,6 @@ library e from "#pkg/vm/testcases/transformations/deferred_loading/e.dart" as e
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -252,7 +241,6 @@ library e from "#pkg/vm/testcases/transformations/deferred_loading/e.dart" as e
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -269,7 +257,6 @@ library c from "#pkg/vm/testcases/transformations/deferred_loading/c.dart" as c
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -291,7 +278,6 @@ library c from "#pkg/vm/testcases/transformations/deferred_loading/c.dart" as c
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -307,7 +293,6 @@ library d from "#pkg/vm/testcases/transformations/deferred_loading/d.dart" as d
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -326,7 +311,6 @@ library d from "#pkg/vm/testcases/transformations/deferred_loading/d.dart" as d
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -342,7 +326,6 @@ library b from "#pkg/vm/testcases/transformations/deferred_loading/b.dart" as b
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -361,7 +344,6 @@ library b from "#pkg/vm/testcases/transformations/deferred_loading/b.dart" as b
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -377,7 +359,6 @@ library a from "#pkg/vm/testcases/transformations/deferred_loading/a.dart" as a
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -399,7 +380,6 @@ library a from "#pkg/vm/testcases/transformations/deferred_loading/a.dart" as a
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -416,7 +396,6 @@ library #lib from "#lib" as #lib {
     final dart.async::_Future<dynamic>* :async_future = new dart.async::_Future::•<dynamic>();
     dart.core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (dart.core::Object*, dart.core::StackTrace*) →* dynamic :async_op_error;
     dart.core::int* :await_jump_var = 0;
@@ -437,7 +416,6 @@ library #lib from "#lib" as #lib {
       on dynamic catch(dynamic exception, dart.core::StackTrace* stack_trace) {
         dart.async::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = dart.async::_asyncStackTraceHelper(:async_op);
     :async_op_then = dart.async::_asyncThenWrapperHelper(:async_op);
     :async_op_error = dart.async::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/async_await.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/async_await.dart.expect
index f1dfad8d9cc..ee9f237a0f7 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/async_await.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/async_await.dart.expect
@@ -12,7 +12,6 @@ class A extends core::Object {
     final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
     core::bool* :is_sync = false;
     FutureOr<dynamic>* :return_value;
-    dynamic :async_stack_trace;
     (dynamic) →* dynamic :async_op_then;
     (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
     core::int* :await_jump_var = 0;
@@ -30,7 +29,6 @@ class A extends core::Object {
       on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
         asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
       }
-    :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
     :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
     :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
     [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -49,7 +47,6 @@ static method baz() → asy::Future<dynamic>* /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -67,7 +64,6 @@ static method baz() → asy::Future<dynamic>* /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
@@ -78,7 +74,6 @@ static method main() → dynamic /* originally async */ {
   final asy::_Future<dynamic>* :async_future = new asy::_Future::•<dynamic>();
   core::bool* :is_sync = false;
   FutureOr<dynamic>* :return_value;
-  dynamic :async_stack_trace;
   (dynamic) →* dynamic :async_op_then;
   (core::Object*, core::StackTrace*) →* dynamic :async_op_error;
   core::int* :await_jump_var = 0;
@@ -100,7 +95,6 @@ static method main() → dynamic /* originally async */ {
     on dynamic catch(dynamic exception, core::StackTrace* stack_trace) {
       asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
     }
-  :async_stack_trace = asy::_asyncStackTraceHelper(:async_op);
   :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
   :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
   [@vm.call-site-attributes.metadata=receiverType:dynamic Function([dynamic, dynamic, dart.core::StackTrace*])*] :async_op.call();
diff --git a/pkg/vm_service/test/async_single_step_exception_test.dart b/pkg/vm_service/test/async_single_step_exception_test.dart
index 189196e971b..b6163269866 100644
--- a/pkg/vm_service/test/async_single_step_exception_test.dart
+++ b/pkg/vm_service/test/async_single_step_exception_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/async_single_step_into_test.dart b/pkg/vm_service/test/async_single_step_into_test.dart
index 90be6df8c5e..36dd15b842a 100644
--- a/pkg/vm_service/test/async_single_step_into_test.dart
+++ b/pkg/vm_service/test/async_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/async_single_step_out_test.dart b/pkg/vm_service/test/async_single_step_out_test.dart
index fe8baed8b21..a0a3d8354d8 100644
--- a/pkg/vm_service/test/async_single_step_out_test.dart
+++ b/pkg/vm_service/test/async_single_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/async_star_single_step_into_test.dart b/pkg/vm_service/test/async_star_single_step_into_test.dart
index 061c2fdb45e..d2d730e1593 100644
--- a/pkg/vm_service/test/async_star_single_step_into_test.dart
+++ b/pkg/vm_service/test/async_star_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/async_star_step_out_test.dart b/pkg/vm_service/test/async_star_step_out_test.dart
index 6e4cde96387..5bb8dde3890 100644
--- a/pkg/vm_service/test/async_star_step_out_test.dart
+++ b/pkg/vm_service/test/async_star_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/async_step_out_test.dart b/pkg/vm_service/test/async_step_out_test.dart
index 3ccfb1d4dd2..8e46584952b 100644
--- a/pkg/vm_service/test/async_step_out_test.dart
+++ b/pkg/vm_service/test/async_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:developer';
 import 'common/service_test_common.dart';
diff --git a/pkg/vm_service/test/common/test_helper.dart b/pkg/vm_service/test/common/test_helper.dart
index 836e3231d67..48d59417bec 100644
--- a/pkg/vm_service/test/common/test_helper.dart
+++ b/pkg/vm_service/test/common/test_helper.dart
@@ -13,14 +13,8 @@ import 'package:test/test.dart';
 import 'service_test_common.dart';
 export 'service_test_common.dart' show IsolateTest, VMTest;
 
-/// Whether to use causal async stacks (if not we use lazy async stacks).
-const bool useCausalAsyncStacks =
-    bool.fromEnvironment('dart.developer.causal_async_stacks');
-
 /// The extra arguments to use
-const List<String> extraDebuggingArgs = useCausalAsyncStacks
-    ? ['--causal-async-stacks', '--no-lazy-async-stacks']
-    : ['--no-causal-async-stacks', '--lazy-async-stacks'];
+const List<String> extraDebuggingArgs = ['--lazy-async-stacks'];
 
 /// Will be set to the http address of the VM's service protocol before
 /// any tests are invoked.
diff --git a/pkg/vm_service/test/get_stack_test.dart b/pkg/vm_service/test/get_stack_test.dart
index 0f659383e3b..5889996ef9d 100644
--- a/pkg/vm_service/test/get_stack_test.dart
+++ b/pkg/vm_service/test/get_stack_test.dart
@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks --verbose_debug
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 
diff --git a/runtime/lib/stacktrace.cc b/runtime/lib/stacktrace.cc
index eaa287cd043..2c75f02b0ae 100644
--- a/runtime/lib/stacktrace.cc
+++ b/runtime/lib/stacktrace.cc
@@ -66,79 +66,17 @@ static StackTracePtr CurrentSyncStackTrace(Thread* thread,
 // Gets current stack trace for `thread`.
 // This functions itself handles the --causel-async-stacks case.
 // For --lazy-async-stacks see `CurrentSyncStackTraceLazy`.
-// For --no-causel-async-stacks see `CurrentSyncStackTrace`.
+// For fallback see `CurrentSyncStackTrace`.
 // Extracts the causal async stack from the thread if any set, then prepends
 // the current sync. stack up until the current async function (if any).
-static StackTracePtr CurrentStackTrace(
-    Thread* thread,
-    bool for_async_function,
-    intptr_t skip_frames = 1,
-    bool causal_async_stacks = FLAG_causal_async_stacks) {
+static StackTracePtr CurrentStackTrace(Thread* thread,
+                                       bool for_async_function,
+                                       intptr_t skip_frames = 1) {
   if (FLAG_lazy_async_stacks) {
     return CurrentSyncStackTraceLazy(thread, skip_frames);
   }
-  if (!causal_async_stacks) {
-    // Return the synchronous stack trace.
-    return CurrentSyncStackTrace(thread, skip_frames);
-  }
-
-  Zone* zone = thread->zone();
-  Code& code = Code::ZoneHandle(zone);
-  Smi& offset = Smi::ZoneHandle(zone);
-  Function& async_function = Function::ZoneHandle(zone);
-  StackTrace& async_stack_trace = StackTrace::ZoneHandle(zone);
-  Array& async_code_array = Array::ZoneHandle(zone);
-  Array& async_pc_offset_array = Array::ZoneHandle(zone);
-
-  StackTraceUtils::ExtractAsyncStackTraceInfo(
-      thread, &async_function, &async_stack_trace, &async_code_array,
-      &async_pc_offset_array);
-
-  // Determine the size of the stack trace.
-  const intptr_t extra_frames = for_async_function ? 1 : 0;
-  bool sync_async_end = false;
-  // Count frames until `async_function` and set whether the async function is
-  // running synchronously (i.e. hasn't yielded yet).
-  const intptr_t synchronous_stack_trace_length = StackTraceUtils::CountFrames(
-      thread, skip_frames, async_function, &sync_async_end);
-
-  ASSERT(synchronous_stack_trace_length > 0);
-
-  const intptr_t capacity = synchronous_stack_trace_length +
-                            extra_frames;  // For the asynchronous gap.
-
-  // Allocate memory for the stack trace.
-  const Array& code_array = Array::ZoneHandle(zone, Array::New(capacity));
-  const Array& pc_offset_array = Array::ZoneHandle(zone, Array::New(capacity));
-
-  intptr_t write_cursor = 0;
-  if (for_async_function) {
-    // Place the asynchronous gap marker at the top of the stack trace.
-    code = StubCode::AsynchronousGapMarker().raw();
-    ASSERT(!code.IsNull());
-    offset = Smi::New(0);
-    code_array.SetAt(write_cursor, code);
-    pc_offset_array.SetAt(write_cursor, offset);
-    write_cursor++;
-  }
-
-  // Prepend: synchronous stack trace + (cached) async stack trace.
-
-  write_cursor +=
-      StackTraceUtils::CollectFrames(thread, code_array, pc_offset_array,
-                                     /*array_offset=*/write_cursor,
-                                     /*count=*/synchronous_stack_trace_length,
-                                     /*skip_frames=*/skip_frames);
-
-  ASSERT(write_cursor == capacity);
-
-  const StackTrace& result = StackTrace::Handle(
-      zone,
-      StackTrace::New(code_array, pc_offset_array,
-                      /*async_link=*/async_stack_trace,
-                      /*skip_sync_start_in_parent_stack=*/sync_async_end));
-
-  return result.raw();
+  // Return the synchronous stack trace.
+  return CurrentSyncStackTrace(thread, skip_frames);
 }
 
 StackTracePtr GetStackTraceForException() {
@@ -150,39 +88,6 @@ DEFINE_NATIVE_ENTRY(StackTrace_current, 0, 0) {
   return CurrentStackTrace(thread, false);
 }
 
-DEFINE_NATIVE_ENTRY(StackTrace_asyncStackTraceHelper, 0, 1) {
-  if (!FLAG_causal_async_stacks) {
-    // If causal async stacks are not enabled we should recognize this method
-    // and never call to the NOP runtime.
-    // See kernel_to_il.cc.
-    UNREACHABLE();
-  }
-#if !defined(PRODUCT)
-  GET_NATIVE_ARGUMENT(Closure, async_op, arguments->NativeArgAt(0));
-  Debugger* debugger = isolate->debugger();
-  if (debugger != NULL) {
-    debugger->MaybeAsyncStepInto(async_op);
-  }
-#endif
-  return CurrentStackTrace(thread, true);
-}
-
-DEFINE_NATIVE_ENTRY(StackTrace_clearAsyncThreadStackTrace, 0, 0) {
-  thread->clear_async_stack_trace();
-  return Object::null();
-}
-
-DEFINE_NATIVE_ENTRY(StackTrace_setAsyncThreadStackTrace, 0, 1) {
-  if (!FLAG_causal_async_stacks) {
-    return Object::null();
-  }
-
-  GET_NON_NULL_NATIVE_ARGUMENT(StackTrace, stack_trace,
-                               arguments->NativeArgAt(0));
-  thread->set_async_stack_trace(stack_trace);
-  return Object::null();
-}
-
 static void AppendFrames(const GrowableObjectArray& code_list,
                          const GrowableObjectArray& pc_offset_list,
                          int skip_frames) {
diff --git a/runtime/observatory/tests/service/async_single_step_exception_test.dart b/runtime/observatory/tests/service/async_single_step_exception_test.dart
index 55bd0638ecb..0fdc18391e5 100644
--- a/runtime/observatory/tests/service/async_single_step_exception_test.dart
+++ b/runtime/observatory/tests/service/async_single_step_exception_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/async_single_step_into_test.dart b/runtime/observatory/tests/service/async_single_step_into_test.dart
index 8d8417f2c3d..7477840499a 100644
--- a/runtime/observatory/tests/service/async_single_step_into_test.dart
+++ b/runtime/observatory/tests/service/async_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/async_single_step_out_test.dart b/runtime/observatory/tests/service/async_single_step_out_test.dart
index 2b51e2494fd..cfeac6c83f9 100644
--- a/runtime/observatory/tests/service/async_single_step_out_test.dart
+++ b/runtime/observatory/tests/service/async_single_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/async_star_single_step_into_test.dart b/runtime/observatory/tests/service/async_star_single_step_into_test.dart
index 65a784d2044..0d99fd55148 100644
--- a/runtime/observatory/tests/service/async_star_single_step_into_test.dart
+++ b/runtime/observatory/tests/service/async_star_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/async_star_step_out_test.dart b/runtime/observatory/tests/service/async_star_step_out_test.dart
index fca9d162804..95ca280c973 100644
--- a/runtime/observatory/tests/service/async_star_step_out_test.dart
+++ b/runtime/observatory/tests/service/async_star_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/async_step_out_test.dart b/runtime/observatory/tests/service/async_step_out_test.dart
index f22f8d8be37..4cce8260cbc 100644
--- a/runtime/observatory/tests/service/async_step_out_test.dart
+++ b/runtime/observatory/tests/service/async_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory/tests/service/awaiter_async_stack_contents_2_test.dart b/runtime/observatory/tests/service/awaiter_async_stack_contents_2_test.dart
index e9b971cb01d..b2d216559a5 100644
--- a/runtime/observatory/tests/service/awaiter_async_stack_contents_2_test.dart
+++ b/runtime/observatory/tests/service/awaiter_async_stack_contents_2_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'package:observatory/models.dart' as M;
@@ -50,28 +50,13 @@ var tests = <IsolateTest>[
       print(v);
     }
 
-    if (useCausalAsyncStacks) {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(4));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:${LINE_B}']));
-      // Suspension point.
-      expect(awaiterFrames[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      // Causal frame.
-      expect(await awaiterFrames[3].toUserString(),
-          stringContainsInOrder(['testMain', '.dart:${LINE_C}']));
-    } else {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(2));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:${LINE_B}']));
-    }
+    expect(awaiterFrames.length, greaterThanOrEqualTo(2));
+    // Awaiter frame.
+    expect(await awaiterFrames[0].toUserString(),
+        stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
+    // Awaiter frame.
+    expect(await awaiterFrames[1].toUserString(),
+        stringContainsInOrder(['helper', '.dart:${LINE_B}']));
   },
 ];
 
diff --git a/runtime/observatory/tests/service/awaiter_async_stack_contents_test.dart b/runtime/observatory/tests/service/awaiter_async_stack_contents_test.dart
index 0aef00ec721..77eeed2997d 100644
--- a/runtime/observatory/tests/service/awaiter_async_stack_contents_test.dart
+++ b/runtime/observatory/tests/service/awaiter_async_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'package:observatory/models.dart' as M;
@@ -53,29 +53,15 @@ var tests = <IsolateTest>[
     ServiceMap stack = await isolate.getStack();
     expect(stack['awaiterFrames'], isNotNull);
     List awaiterFrames = stack['awaiterFrames'];
-    if (useCausalAsyncStacks) {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(4));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:$LINE_C']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:$LINE_D']));
-      // Suspension point.
-      expect(awaiterFrames[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      // Causal frame.
-      expect(await awaiterFrames[3].toUserString(),
-          stringContainsInOrder(['testMain', '.dart:$LINE_B']));
-    } else {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(2));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:$LINE_C']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:$LINE_D']));
-      // "helper" is not await'ed.
-    }
+
+    expect(awaiterFrames.length, greaterThanOrEqualTo(2));
+    // Awaiter frame.
+    expect(await awaiterFrames[0].toUserString(),
+        stringContainsInOrder(['foobar', '.dart:$LINE_C']));
+    // Awaiter frame.
+    expect(await awaiterFrames[1].toUserString(),
+        stringContainsInOrder(['helper', '.dart:$LINE_D']));
+    // "helper" is not await'ed.
   },
 ];
 
diff --git a/runtime/observatory/tests/service/causal_async_stack_contents_test.dart b/runtime/observatory/tests/service/causal_async_stack_contents_test.dart
index ed77ae6501e..3e4a8eb54e8 100644
--- a/runtime/observatory/tests/service/causal_async_stack_contents_test.dart
+++ b/runtime/observatory/tests/service/causal_async_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory/models.dart' as M;
@@ -48,14 +48,8 @@ var tests = <IsolateTest>[
     // Has causal frames (we are inside an async function)
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack[0].toString(), contains('helper'));
-      expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[2].toString(), contains('testMain'));
-    } else {
-      expect(asyncStack[0].toString(), contains('helper'));
-      // "helper" is not await'ed.
-    }
+    expect(asyncStack[0].toString(), contains('helper'));
+    // "helper" is not await'ed.
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -65,19 +59,9 @@ var tests = <IsolateTest>[
     // Has causal frames (we are inside a function called by an async function)
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack[0].toString(), contains('foobar'));
-      expect(asyncStack[1].toString(), contains('helper'));
-      expect(asyncStack[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[3].toString(), contains('testMain'));
-      expect(await asyncStack[0].location.toUserString(), contains('.dart:20'));
-      expect(await asyncStack[1].location.toUserString(), contains('.dart:27'));
-      expect(await asyncStack[3].location.toUserString(), contains('.dart:32'));
-    } else {
-      expect(asyncStack[0].toString(), contains('foobar'));
-      expect(asyncStack[1].toString(), contains('helper'));
-      // "helper" is not await'ed.
-    }
+    expect(asyncStack[0].toString(), contains('foobar'));
+    expect(asyncStack[1].toString(), contains('helper'));
+    // "helper" is not await'ed.
   },
 ];
 
diff --git a/runtime/observatory/tests/service/causal_async_stack_presence_test.dart b/runtime/observatory/tests/service/causal_async_stack_presence_test.dart
index 0e57f476c4f..3a90e4a62b0 100644
--- a/runtime/observatory/tests/service/causal_async_stack_presence_test.dart
+++ b/runtime/observatory/tests/service/causal_async_stack_presence_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory/service_io.dart';
diff --git a/runtime/observatory/tests/service/causal_async_star_stack_contents_test.dart b/runtime/observatory/tests/service/causal_async_star_stack_contents_test.dart
index 8efceccb3e5..8d66a17aabe 100644
--- a/runtime/observatory/tests/service/causal_async_star_stack_contents_test.dart
+++ b/runtime/observatory/tests/service/causal_async_star_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory/models.dart' as M;
@@ -44,16 +44,9 @@ var tests = <IsolateTest>[
     // No causal frames because we are in a completely synchronous stack.
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack.length, greaterThanOrEqualTo(3));
-      expect(asyncStack[0].toString(), contains('helper'));
-      expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[2].toString(), contains('testMain'));
-    } else {
-      expect(asyncStack.length, greaterThanOrEqualTo(1));
-      expect(asyncStack[0].toString(), contains('helper'));
-      // helper isn't awaited.
-    }
+    expect(asyncStack.length, greaterThanOrEqualTo(1));
+    expect(asyncStack[0].toString(), contains('helper'));
+    // helper isn't awaited.
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -68,10 +61,6 @@ var tests = <IsolateTest>[
     expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
     expect(asyncStack[2].toString(), contains('helper'));
     expect(asyncStack[3].kind, equals(M.FrameKind.asyncSuspensionMarker));
-    if (useCausalAsyncStacks) {
-      // helper isn't awaited.
-      expect(asyncStack[4].toString(), contains('testMain'));
-    }
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -93,12 +82,6 @@ var tests = <IsolateTest>[
     expect(asyncStack[2].toString(), contains('helper'));
     expect(await asyncStack[2].location.toUserString(), contains('.dart:30'));
     expect(asyncStack[3].kind, equals(M.FrameKind.asyncSuspensionMarker));
-    if (useCausalAsyncStacks) {
-      // helper isn't awaited.
-      expect(asyncStack.length, greaterThanOrEqualTo(5));
-      expect(asyncStack[4].toString(), contains('testMain'));
-      expect(await asyncStack[4].location.toUserString(), contains('.dart:36'));
-    }
   },
 ];
 
diff --git a/runtime/observatory/tests/service/causal_async_star_stack_presence_test.dart b/runtime/observatory/tests/service/causal_async_star_stack_presence_test.dart
index df29834ca54..4d3e4486590 100644
--- a/runtime/observatory/tests/service/causal_async_star_stack_presence_test.dart
+++ b/runtime/observatory/tests/service/causal_async_star_stack_presence_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory/service_io.dart';
diff --git a/runtime/observatory/tests/service/get_stack_limit_rpc_test.dart b/runtime/observatory/tests/service/get_stack_limit_rpc_test.dart
index 99a8bf1c1dd..b1ccb4ff817 100644
--- a/runtime/observatory/tests/service/get_stack_limit_rpc_test.dart
+++ b/runtime/observatory/tests/service/get_stack_limit_rpc_test.dart
@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+// VMOptions=--lazy-async-stacks
 
 import 'dart:async';
 import 'dart:developer';
@@ -13,31 +13,29 @@ import 'package:test/test.dart';
 import 'service_test_common.dart';
 import 'test_helper.dart';
 
-bar(int depth) {
+bar(int depth) async {
   if (depth == 21) {
     debugger();
     return;
   }
-  foo(depth + 1);
+  await foo(depth + 1);
 }
 
-foo(int depth) {
-  bar(depth + 1);
+foo(int depth) async {
+  if (depth == 10) {
+    // Yield once to force the rest to run async.
+    await 0;
+  }
+  await bar(depth + 1);
 }
 
-testMain() {
-  foo(0);
+testMain() async {
+  await foo(0);
 }
 
-verifyStack(List frames, int numFrames) {
-  for (int i = 0; i < frames.length && i < numFrames; ++i) {
-    final frame = frames[i];
-    if (i < 22) {
-      expect(frame.function!.qualifiedName, (i % 2) == 0 ? 'bar' : 'foo');
-    } else if (i == 22) {
-      expect(frame.function!.qualifiedName, 'testMain');
-      break;
-    }
+verifyStack(List frames, List<String> expectedNames) {
+  for (int i = 0; i < frames.length && i < expectedNames.length; ++i) {
+    expect(frames[i].function!.qualifiedName, expectedNames[i]);
   }
 }
 
@@ -57,10 +55,14 @@ var tests = <IsolateTest>[
     var awaiterFrames = stack['awaiterFrames'];
     expect(frames.length, greaterThanOrEqualTo(20));
     expect(asyncFrames.length, greaterThan(frames.length));
-    expect(awaiterFrames.length, greaterThan(frames.length));
+    expect(awaiterFrames.length, 13);
     expect(stack['truncated'], false);
-
-    verifyStack(frames, frames.length);
+    verifyStack(frames, [
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      '_RootZone.runUnary', // Internal async. mech. ..
+    ]);
 
     final fullStackLength = frames.length;
 
@@ -75,7 +77,12 @@ var tests = <IsolateTest>[
     expect(asyncFrames.length, fullStackLength + 1);
     expect(asyncFrames.length, fullStackLength + 1);
     expect(stack['truncated'], true);
-    verifyStack(frames, fullStackLength);
+    verifyStack(frames, [
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      '_RootZone.runUnary', // Internal async. mech. ..
+    ]);
 
     // Try a limit < actual stack depth and expect to get a stack of depth
     // 'limit'.
@@ -88,7 +95,18 @@ var tests = <IsolateTest>[
     expect(asyncFrames.length, 10);
     expect(awaiterFrames.length, 10);
     expect(stack['truncated'], true);
-    verifyStack(frames, 10);
+    verifyStack(frames, [
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+    ]);
   },
 // Invalid limit
   (Isolate isolate) async {
diff --git a/runtime/observatory/tests/service/next_through_simple_async_test.dart b/runtime/observatory/tests/service/next_through_simple_async_test.dart
index 5a3ac873d54..bc2c3d537e1 100644
--- a/runtime/observatory/tests/service/next_through_simple_async_test.dart
+++ b/runtime/observatory/tests/service/next_through_simple_async_test.dart
@@ -1,19 +1,17 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'test_helper.dart';
 import 'service_test_common.dart';
 import 'dart:io';
 
-const int LINE_A = 16;
+const int LINE_A = 14;
 const String file = "next_through_simple_async_test.dart";
 
-// line A is at the "code() async" line
-code() async {
+code() async {  // LINE_A
   File f = new File(Platform.script.toFilePath());
   DateTime modified = await f.lastModified();
   bool exists = await f.exists();
diff --git a/runtime/observatory/tests/service/next_through_simple_async_with_returns_test.dart b/runtime/observatory/tests/service/next_through_simple_async_with_returns_test.dart
index 68dca68b801..9a3f2348faa 100644
--- a/runtime/observatory/tests/service/next_through_simple_async_with_returns_test.dart
+++ b/runtime/observatory/tests/service/next_through_simple_async_with_returns_test.dart
@@ -1,19 +1,17 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'test_helper.dart';
 import 'service_test_common.dart';
 import 'dart:io';
 
-const int LINE_A = 16;
+const int LINE_A = 14;
 const String file = "next_through_simple_async_with_returns_test.dart";
 
-// line A is at the "code() async" line
-code() async {
+code() async {  // LINE_A
   File f = new File(Platform.script.toFilePath());
   bool exists = await f.exists();
   if (exists) {
diff --git a/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions2_test.dart b/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions2_test.dart
index e922a19c7e2..67f69012ccd 100644
--- a/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions2_test.dart
+++ b/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions2_test.dart
@@ -1,10 +1,9 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks --optimization-counter-threshold=5
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks --optimization-counter-threshold=5
+//
+// VMOptions=--async_debugger --lazy-async-stacks
+// VMOptions=--async_debugger --lazy-async-stacks --optimization-counter-threshold=5
 
 import 'package:observatory/service_io.dart';
 import 'package:observatory/models.dart' as M;
@@ -12,12 +11,12 @@ import 'package:test/test.dart';
 import 'test_helper.dart';
 import 'service_test_common.dart';
 
-const LINE_A = 37;
+const LINE_A = 36;
 
 class Foo {}
 
 doThrow() {
-  throw "TheException"; // Line 13.
+  throw "TheException";
   return "end of doThrow";
 }
 
diff --git a/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions_test.dart b/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions_test.dart
index 05cf75029d7..fe636dd16fa 100644
--- a/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions_test.dart
+++ b/runtime/observatory/tests/service/pause_on_unhandled_async_exceptions_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async_debugger --lazy-async-stacks
 
 import 'package:observatory/service_io.dart';
 import 'package:observatory/models.dart' as M;
@@ -15,7 +15,7 @@ const LINE_A = 36;
 class Foo {}
 
 doThrow() {
-  throw "TheException"; // Line 13.
+  throw "TheException";
   return "end of doThrow";
 }
 
@@ -45,21 +45,10 @@ var tests = <IsolateTest>[
     var stack = await isolate.getStack();
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack.length, greaterThanOrEqualTo(4));
-      expect(asyncStack[0].toString(), contains('doThrow'));
-      expect(asyncStack[1].toString(), contains('asyncThrower'));
-      expect(asyncStack[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[3].toString(), contains('testeeMain'));
-      // We've stopped at LINE_A.
-      expect(await asyncStack[3].location.toUserString(),
-          contains('.dart:$LINE_A'));
-    } else {
-      expect(asyncStack.length, greaterThanOrEqualTo(2));
-      expect(asyncStack[0].toString(), contains('doThrow'));
-      expect(asyncStack[1].toString(), contains('asyncThrower'));
-      // There was no await'er for "doThrow()".
-    }
+    expect(asyncStack.length, greaterThanOrEqualTo(2));
+    expect(asyncStack[0].toString(), contains('doThrow'));
+    expect(asyncStack[1].toString(), contains('asyncThrower'));
+    // There was no await'er for "doThrow()".
   }
 ];
 
diff --git a/runtime/observatory/tests/service/test_helper.dart b/runtime/observatory/tests/service/test_helper.dart
index 805e7fecb1d..3143df6d5e9 100644
--- a/runtime/observatory/tests/service/test_helper.dart
+++ b/runtime/observatory/tests/service/test_helper.dart
@@ -13,17 +13,11 @@ import 'package:test/test.dart';
 import 'service_test_common.dart';
 export 'service_test_common.dart' show DDSTest, IsolateTest, VMTest;
 
-/// Whether to use causal async stacks (if not we use lazy async stacks).
-const bool useCausalAsyncStacks =
-    const bool.fromEnvironment('dart.developer.causal_async_stacks');
-
 /// Determines whether DDS is enabled for this test run.
 const bool useDds = const bool.fromEnvironment('USE_DDS');
 
 /// The extra arguments to use
-const List<String> extraDebuggingArgs = useCausalAsyncStacks
-    ? const ['--causal-async-stacks', '--no-lazy-async-stacks']
-    : const ['--no-causal-async-stacks', '--lazy-async-stacks'];
+const List<String> extraDebuggingArgs = ['--lazy-async-stacks'];
 
 /// Will be set to the http address of the VM's service protocol before
 /// any tests are invoked.
diff --git a/runtime/observatory_2/tests/service_2/async_single_step_exception_test.dart b/runtime/observatory_2/tests/service_2/async_single_step_exception_test.dart
index fdc490eff8a..841afab9fa3 100644
--- a/runtime/observatory_2/tests/service_2/async_single_step_exception_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_single_step_exception_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/async_single_step_into_test.dart b/runtime/observatory_2/tests/service_2/async_single_step_into_test.dart
index 8d8417f2c3d..7477840499a 100644
--- a/runtime/observatory_2/tests/service_2/async_single_step_into_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/async_single_step_out_test.dart b/runtime/observatory_2/tests/service_2/async_single_step_out_test.dart
index 2b51e2494fd..cfeac6c83f9 100644
--- a/runtime/observatory_2/tests/service_2/async_single_step_out_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_single_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/async_star_single_step_into_test.dart b/runtime/observatory_2/tests/service_2/async_star_single_step_into_test.dart
index 65a784d2044..0d99fd55148 100644
--- a/runtime/observatory_2/tests/service_2/async_star_single_step_into_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_star_single_step_into_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/async_star_step_out_test.dart b/runtime/observatory_2/tests/service_2/async_star_step_out_test.dart
index fca9d162804..95ca280c973 100644
--- a/runtime/observatory_2/tests/service_2/async_star_step_out_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_star_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/async_step_out_test.dart b/runtime/observatory_2/tests/service_2/async_step_out_test.dart
index f22f8d8be37..4cce8260cbc 100644
--- a/runtime/observatory_2/tests/service_2/async_step_out_test.dart
+++ b/runtime/observatory_2/tests/service_2/async_step_out_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'service_test_common.dart';
diff --git a/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_2_test.dart b/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_2_test.dart
index be22e8b10e1..0df05fd3013 100644
--- a/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_2_test.dart
+++ b/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_2_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'package:observatory_2/models.dart' as M;
@@ -50,28 +50,13 @@ var tests = <IsolateTest>[
       print(v);
     }
 
-    if (useCausalAsyncStacks) {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(4));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:${LINE_B}']));
-      // Suspension point.
-      expect(awaiterFrames[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      // Causal frame.
-      expect(await awaiterFrames[3].toUserString(),
-          stringContainsInOrder(['testMain', '.dart:${LINE_C}']));
-    } else {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(2));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:${LINE_B}']));
-    }
+    expect(awaiterFrames.length, greaterThanOrEqualTo(2));
+    // Awaiter frame.
+    expect(await awaiterFrames[0].toUserString(),
+        stringContainsInOrder(['foobar', '.dart:${LINE_A}']));
+    // Awaiter frame.
+    expect(await awaiterFrames[1].toUserString(),
+        stringContainsInOrder(['helper', '.dart:${LINE_B}']));
   },
 ];
 
diff --git a/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_test.dart b/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_test.dart
index 5f189452d20..9e0f8f3f52d 100644
--- a/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_test.dart
+++ b/runtime/observatory_2/tests/service_2/awaiter_async_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async-debugger --verbose-debug --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async-debugger --verbose-debug --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async-debugger --verbose-debug --lazy-async-stacks
 
 import 'dart:developer';
 import 'package:observatory_2/models.dart' as M;
@@ -53,29 +53,14 @@ var tests = <IsolateTest>[
     ServiceMap stack = await isolate.getStack();
     expect(stack['awaiterFrames'], isNotNull);
     List awaiterFrames = stack['awaiterFrames'];
-    if (useCausalAsyncStacks) {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(4));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:$LINE_C']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:$LINE_D']));
-      // Suspension point.
-      expect(awaiterFrames[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      // Causal frame.
-      expect(await awaiterFrames[3].toUserString(),
-          stringContainsInOrder(['testMain', '.dart:$LINE_B']));
-    } else {
-      expect(awaiterFrames.length, greaterThanOrEqualTo(2));
-      // Awaiter frame.
-      expect(await awaiterFrames[0].toUserString(),
-          stringContainsInOrder(['foobar', '.dart:$LINE_C']));
-      // Awaiter frame.
-      expect(await awaiterFrames[1].toUserString(),
-          stringContainsInOrder(['helper', '.dart:$LINE_D']));
-      // "helper" is not await'ed.
-    }
+    expect(awaiterFrames.length, greaterThanOrEqualTo(2));
+    // Awaiter frame.
+    expect(await awaiterFrames[0].toUserString(),
+        stringContainsInOrder(['foobar', '.dart:$LINE_C']));
+    // Awaiter frame.
+    expect(await awaiterFrames[1].toUserString(),
+        stringContainsInOrder(['helper', '.dart:$LINE_D']));
+    // "helper" is not await'ed.
   },
 ];
 
diff --git a/runtime/observatory_2/tests/service_2/causal_async_stack_contents_test.dart b/runtime/observatory_2/tests/service_2/causal_async_stack_contents_test.dart
index 067887dc6ec..7523c0f1db5 100644
--- a/runtime/observatory_2/tests/service_2/causal_async_stack_contents_test.dart
+++ b/runtime/observatory_2/tests/service_2/causal_async_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory_2/models.dart' as M;
@@ -48,14 +48,8 @@ var tests = <IsolateTest>[
     // Has causal frames (we are inside an async function)
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack[0].toString(), contains('helper'));
-      expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[2].toString(), contains('testMain'));
-    } else {
-      expect(asyncStack[0].toString(), contains('helper'));
-      // "helper" is not await'ed.
-    }
+    expect(asyncStack[0].toString(), contains('helper'));
+    // "helper" is not await'ed.
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -65,19 +59,9 @@ var tests = <IsolateTest>[
     // Has causal frames (we are inside a function called by an async function)
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack[0].toString(), contains('foobar'));
-      expect(asyncStack[1].toString(), contains('helper'));
-      expect(asyncStack[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[3].toString(), contains('testMain'));
-      expect(await asyncStack[0].location.toUserString(), contains('.dart:20'));
-      expect(await asyncStack[1].location.toUserString(), contains('.dart:27'));
-      expect(await asyncStack[3].location.toUserString(), contains('.dart:32'));
-    } else {
-      expect(asyncStack[0].toString(), contains('foobar'));
-      expect(asyncStack[1].toString(), contains('helper'));
-      // "helper" is not await'ed.
-    }
+    expect(asyncStack[0].toString(), contains('foobar'));
+    expect(asyncStack[1].toString(), contains('helper'));
+    // "helper" is not await'ed.
   },
 ];
 
diff --git a/runtime/observatory_2/tests/service_2/causal_async_stack_presence_test.dart b/runtime/observatory_2/tests/service_2/causal_async_stack_presence_test.dart
index c37359e0e6b..f52f4a1fbd2 100644
--- a/runtime/observatory_2/tests/service_2/causal_async_stack_presence_test.dart
+++ b/runtime/observatory_2/tests/service_2/causal_async_stack_presence_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory_2/service_io.dart';
diff --git a/runtime/observatory_2/tests/service_2/causal_async_star_stack_contents_test.dart b/runtime/observatory_2/tests/service_2/causal_async_star_stack_contents_test.dart
index 4474624da18..5044d576970 100644
--- a/runtime/observatory_2/tests/service_2/causal_async_star_stack_contents_test.dart
+++ b/runtime/observatory_2/tests/service_2/causal_async_star_stack_contents_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory_2/models.dart' as M;
@@ -44,16 +44,9 @@ var tests = <IsolateTest>[
     // No causal frames because we are in a completely synchronous stack.
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack.length, greaterThanOrEqualTo(3));
-      expect(asyncStack[0].toString(), contains('helper'));
-      expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[2].toString(), contains('testMain'));
-    } else {
-      expect(asyncStack.length, greaterThanOrEqualTo(1));
-      expect(asyncStack[0].toString(), contains('helper'));
-      // helper isn't awaited.
-    }
+    expect(asyncStack.length, greaterThanOrEqualTo(1));
+    expect(asyncStack[0].toString(), contains('helper'));
+    // helper isn't awaited.
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -68,10 +61,7 @@ var tests = <IsolateTest>[
     expect(asyncStack[1].kind, equals(M.FrameKind.asyncSuspensionMarker));
     expect(asyncStack[2].toString(), contains('helper'));
     expect(asyncStack[3].kind, equals(M.FrameKind.asyncSuspensionMarker));
-    if (useCausalAsyncStacks) {
-      // helper isn't awaited.
-      expect(asyncStack[4].toString(), contains('testMain'));
-    }
+    // helper isn't awaited.
   },
   resumeIsolate,
   hasStoppedAtBreakpoint,
@@ -93,12 +83,7 @@ var tests = <IsolateTest>[
     expect(asyncStack[2].toString(), contains('helper'));
     expect(await asyncStack[2].location.toUserString(), contains('.dart:30'));
     expect(asyncStack[3].kind, equals(M.FrameKind.asyncSuspensionMarker));
-    if (useCausalAsyncStacks) {
-      // helper isn't awaited.
-      expect(asyncStack.length, greaterThanOrEqualTo(5));
-      expect(asyncStack[4].toString(), contains('testMain'));
-      expect(await asyncStack[4].location.toUserString(), contains('.dart:36'));
-    }
+    // helper isn't awaited.
   },
 ];
 
diff --git a/runtime/observatory_2/tests/service_2/causal_async_star_stack_presence_test.dart b/runtime/observatory_2/tests/service_2/causal_async_star_stack_presence_test.dart
index db19b2ca579..7fb385ae89f 100644
--- a/runtime/observatory_2/tests/service_2/causal_async_star_stack_presence_test.dart
+++ b/runtime/observatory_2/tests/service_2/causal_async_star_stack_presence_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks --verbose_debug
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks --verbose_debug
+//
+// VMOptions=--lazy-async-stacks --verbose_debug
 
 import 'dart:developer';
 import 'package:observatory_2/service_io.dart';
diff --git a/runtime/observatory_2/tests/service_2/get_stack_limit_rpc_test.dart b/runtime/observatory_2/tests/service_2/get_stack_limit_rpc_test.dart
index 5248ebc99cd..33766da8f43 100644
--- a/runtime/observatory_2/tests/service_2/get_stack_limit_rpc_test.dart
+++ b/runtime/observatory_2/tests/service_2/get_stack_limit_rpc_test.dart
@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+// VMOptions=--lazy-async-stacks
 
 import 'dart:async';
 import 'dart:developer';
@@ -13,31 +13,29 @@ import 'package:test/test.dart';
 import 'service_test_common.dart';
 import 'test_helper.dart';
 
-bar(int depth) {
+bar(int depth) async {
   if (depth == 21) {
     debugger();
     return;
   }
-  foo(depth + 1);
+  await foo(depth + 1);
 }
 
-foo(int depth) {
-  bar(depth + 1);
+foo(int depth) async {
+  if (depth == 10) {
+    // Yield once to force the rest to run async.
+    await 0;
+  }
+  await bar(depth + 1);
 }
 
-testMain() {
-  foo(0);
+testMain() async {
+  await foo(0);
 }
 
-verifyStack(List frames, int numFrames) {
-  for (int i = 0; i < frames.length && i < numFrames; ++i) {
-    final frame = frames[i];
-    if (i < 22) {
-      expect(frame.function.qualifiedName, (i % 2) == 0 ? 'bar' : 'foo');
-    } else if (i == 22) {
-      expect(frame.function.qualifiedName, 'testMain');
-      break;
-    }
+verifyStack(List frames, List<String> expectedNames) {
+  for (int i = 0; i < frames.length && i < expectedNames.length; ++i) {
+    expect(frames[i].function.qualifiedName, expectedNames[i]);
   }
 }
 
@@ -57,10 +55,14 @@ var tests = <IsolateTest>[
     var awaiterFrames = stack['awaiterFrames'];
     expect(frames.length, greaterThanOrEqualTo(20));
     expect(asyncFrames.length, greaterThan(frames.length));
-    expect(awaiterFrames.length, greaterThan(frames.length));
+    expect(awaiterFrames.length, 13);
     expect(stack['truncated'], false);
-
-    verifyStack(frames, frames.length);
+    verifyStack(frames, [
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      '_RootZone.runUnary', // Internal async. mech. ..
+    ]);
 
     final fullStackLength = frames.length;
 
@@ -75,7 +77,12 @@ var tests = <IsolateTest>[
     expect(asyncFrames.length, fullStackLength + 1);
     expect(asyncFrames.length, fullStackLength + 1);
     expect(stack['truncated'], true);
-    verifyStack(frames, fullStackLength);
+    verifyStack(frames, [
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      'bar.async_op', 'foo.async_op', 'bar.async_op', 'foo.async_op',
+      '_RootZone.runUnary', // Internal async. mech. ..
+    ]);
 
     // Try a limit < actual stack depth and expect to get a stack of depth
     // 'limit'.
@@ -88,7 +95,18 @@ var tests = <IsolateTest>[
     expect(asyncFrames.length, 10);
     expect(awaiterFrames.length, 10);
     expect(stack['truncated'], true);
-    verifyStack(frames, 10);
+    verifyStack(frames, [
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+      'bar.async_op',
+      'foo.async_op',
+    ]);
   },
 // Invalid limit
   (Isolate isolate) async {
diff --git a/runtime/observatory_2/tests/service_2/next_through_simple_async_test.dart b/runtime/observatory_2/tests/service_2/next_through_simple_async_test.dart
index 5a3ac873d54..bc2c3d537e1 100644
--- a/runtime/observatory_2/tests/service_2/next_through_simple_async_test.dart
+++ b/runtime/observatory_2/tests/service_2/next_through_simple_async_test.dart
@@ -1,19 +1,17 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'test_helper.dart';
 import 'service_test_common.dart';
 import 'dart:io';
 
-const int LINE_A = 16;
+const int LINE_A = 14;
 const String file = "next_through_simple_async_test.dart";
 
-// line A is at the "code() async" line
-code() async {
+code() async {  // LINE_A
   File f = new File(Platform.script.toFilePath());
   DateTime modified = await f.lastModified();
   bool exists = await f.exists();
diff --git a/runtime/observatory_2/tests/service_2/next_through_simple_async_with_returns_test.dart b/runtime/observatory_2/tests/service_2/next_through_simple_async_with_returns_test.dart
index 68dca68b801..9a3f2348faa 100644
--- a/runtime/observatory_2/tests/service_2/next_through_simple_async_with_returns_test.dart
+++ b/runtime/observatory_2/tests/service_2/next_through_simple_async_with_returns_test.dart
@@ -1,19 +1,17 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'test_helper.dart';
 import 'service_test_common.dart';
 import 'dart:io';
 
-const int LINE_A = 16;
+const int LINE_A = 14;
 const String file = "next_through_simple_async_with_returns_test.dart";
 
-// line A is at the "code() async" line
-code() async {
+code() async {  // LINE_A
   File f = new File(Platform.script.toFilePath());
   bool exists = await f.exists();
   if (exists) {
diff --git a/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions2_test.dart b/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions2_test.dart
index fa4bf52acee..50d95370113 100644
--- a/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions2_test.dart
+++ b/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions2_test.dart
@@ -1,10 +1,9 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks --optimization-counter-threshold=5
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks --optimization-counter-threshold=5
+//
+// VMOptions=--async_debugger --lazy-async-stacks
+// VMOptions=--async_debugger --lazy-async-stacks --optimization-counter-threshold=5
 
 import 'package:observatory_2/service_io.dart';
 import 'package:observatory_2/models.dart' as M;
@@ -12,12 +11,12 @@ import 'package:test/test.dart';
 import 'test_helper.dart';
 import 'service_test_common.dart';
 
-const LINE_A = 37;
+const LINE_A = 36;
 
 class Foo {}
 
 doThrow() {
-  throw "TheException"; // Line 13.
+  throw "TheException";
   return "end of doThrow";
 }
 
diff --git a/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions_test.dart b/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions_test.dart
index da161265264..d179cb65c13 100644
--- a/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions_test.dart
+++ b/runtime/observatory_2/tests/service_2/pause_on_unhandled_async_exceptions_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--async_debugger --no-causal-async-stacks --lazy-async-stacks
-// VMOptions=--async_debugger --causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--async_debugger --lazy-async-stacks
 
 import 'package:observatory_2/service_io.dart';
 import 'package:observatory_2/models.dart' as M;
@@ -15,7 +15,7 @@ const LINE_A = 36;
 class Foo {}
 
 doThrow() {
-  throw "TheException"; // Line 13.
+  throw "TheException";
   return "end of doThrow";
 }
 
@@ -45,21 +45,10 @@ var tests = <IsolateTest>[
     var stack = await isolate.getStack();
     expect(stack['asyncCausalFrames'], isNotNull);
     var asyncStack = stack['asyncCausalFrames'];
-    if (useCausalAsyncStacks) {
-      expect(asyncStack.length, greaterThanOrEqualTo(4));
-      expect(asyncStack[0].toString(), contains('doThrow'));
-      expect(asyncStack[1].toString(), contains('asyncThrower'));
-      expect(asyncStack[2].kind, equals(M.FrameKind.asyncSuspensionMarker));
-      expect(asyncStack[3].toString(), contains('testeeMain'));
-      // We've stopped at LINE_A.
-      expect(await asyncStack[3].location.toUserString(),
-          contains('.dart:$LINE_A'));
-    } else {
-      expect(asyncStack.length, greaterThanOrEqualTo(2));
-      expect(asyncStack[0].toString(), contains('doThrow'));
-      expect(asyncStack[1].toString(), contains('asyncThrower'));
-      // There was no await'er for "doThrow()".
-    }
+    expect(asyncStack.length, greaterThanOrEqualTo(2));
+    expect(asyncStack[0].toString(), contains('doThrow'));
+    expect(asyncStack[1].toString(), contains('asyncThrower'));
+    // There was no await'er for "doThrow()".
   }
 ];
 
diff --git a/runtime/observatory_2/tests/service_2/test_helper.dart b/runtime/observatory_2/tests/service_2/test_helper.dart
index 18f345ec04e..0a352fef711 100644
--- a/runtime/observatory_2/tests/service_2/test_helper.dart
+++ b/runtime/observatory_2/tests/service_2/test_helper.dart
@@ -13,17 +13,11 @@ import 'package:test/test.dart';
 import 'service_test_common.dart';
 export 'service_test_common.dart' show DDSTest, IsolateTest, VMTest;
 
-/// Whether to use causal async stacks (if not we use lazy async stacks).
-const bool useCausalAsyncStacks =
-    const bool.fromEnvironment('dart.developer.causal_async_stacks');
-
 /// Determines whether DDS is enabled for this test run.
 const bool useDds = const bool.fromEnvironment('USE_DDS');
 
 /// The extra arguments to use
-const List<String> extraDebuggingArgs = useCausalAsyncStacks
-    ? const ['--causal-async-stacks', '--no-lazy-async-stacks']
-    : const ['--no-causal-async-stacks', '--lazy-async-stacks'];
+const List<String> extraDebuggingArgs = ['--lazy-async-stacks'];
 
 /// Will be set to the http address of the VM's service protocol before
 /// any tests are invoked.
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
index 2ec438e2cab..5f18af83c3e 100644
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
+++ b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_lazy_debug.so --lazy-async-stacks --no-causal-async-stacks --no-use-bare-instructions
+//
+// VMOptions=--dwarf-stack-traces --save-debugging-info=async_lazy_debug.so --lazy-async-stacks --no-use-bare-instructions
 
 import 'dart:async';
 import 'dart:io';
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_test.dart
index 3155257b077..26805f15fa4 100644
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_test.dart
+++ b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_lazy_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:async';
 
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
index f65de8494b8..c9dbb093dff 100644
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
+++ b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_no_causal_debug.so --no-causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--dwarf-stack-traces --save-debugging-info=async_no_causal_debug.so --no-lazy-async-stacks
 
 import 'dart:async';
 import 'dart:io';
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_test.dart
index 7cc8cf0ee97..84848c943ab 100644
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_test.dart
+++ b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_no_causal_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--no-lazy-async-stacks
 
 import 'dart:async';
 
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_non_symbolic_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_non_symbolic_test.dart
deleted file mode 100644
index cdb783a4104..00000000000
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_non_symbolic_test.dart
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_causal_debug.so --causal-async-stacks --no-lazy-async-stacks
-
-import 'dart:async';
-import 'dart:io';
-
-import 'utils.dart';
-
-Future<void> main(List<String> args) async {
-  // We won't have access to the debugging info file on Android.
-  if (Platform.isAndroid) return;
-
-  await doTestsCausal('async_causal_debug.so');
-}
diff --git a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_test.dart b/runtime/tests/vm/dart/causal_stacks/async_throws_stack_test.dart
deleted file mode 100644
index 6d25d366615..00000000000
--- a/runtime/tests/vm/dart/causal_stacks/async_throws_stack_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
-
-import 'dart:async';
-
-import 'utils.dart';
-
-Future<void> main(List<String> args) async => await doTestsCausal();
diff --git a/runtime/tests/vm/dart/causal_stacks/utils.dart b/runtime/tests/vm/dart/causal_stacks/utils.dart
index c77ce924ebb..73ffe1d5a60 100644
--- a/runtime/tests/vm/dart/causal_stacks/utils.dart
+++ b/runtime/tests/vm/dart/causal_stacks/utils.dart
@@ -285,520 +285,7 @@ Future<void> doTestAwaitCatchError(Future f(), List<String> expectedStack,
 // Test "Suites":
 // ----
 
-// For: --causal-async-stacks
-Future<void> doTestsCausal([String? debugInfoFilename]) async {
-  final allYieldExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      allYield3 \(.*/utils.dart:39(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      allYield2 \(.*/utils.dart:34(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      allYield \(.*/utils.dart:29(:9)?\)$',
-    r'^<asynchronous suspension>$',
-  ];
-  await doTestAwait(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final noYieldsExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      noYields3 \(.*/utils.dart:54(:3)?\)$',
-    r'^#2      noYields2 \(.*/utils.dart:50(:9)?\)$',
-    r'^#3      noYields \(.*/utils.dart:46(:9)?\)$',
-  ];
-  await doTestAwait(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final mixedYieldsExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      mixedYields3 \(.*/utils.dart:70(:10)?\)$',
-    r'^#2      mixedYields2 \(.*/utils.dart:66(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      mixedYields \(.*/utils.dart:61(:9)?\)$',
-  ];
-  await doTestAwait(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final syncSuffixExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      syncSuffix3 \(.*/utils.dart:86(:10)?\)$',
-    r'^#2      syncSuffix2 \(.*/utils.dart:82(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      syncSuffix \(.*/utils.dart:77(:9)?\)$',
-  ];
-  await doTestAwait(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final nonAsyncNoStackExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      nonAsyncNoStack2.<anonymous closure> ',
-    r'^#2      _RootZone.runUnary ',
-    r'^#3      _FutureListener.handleValue ',
-    r'^#4      Future._propagateToListeners.handleValueCallback ',
-    r'^#5      Future._propagateToListeners ',
-    r'^#6      Future._completeWithValue ',
-    r'^#7      Future._asyncCompleteWithValue.<anonymous closure> ',
-    r'^#8      _microtaskLoop ',
-    r'^#9      _startMicrotaskLoop ',
-    r'^#10     _runPendingImmediateCallback ',
-    r'^#11     _RawReceivePortImpl._handleMessage ',
-  ];
-  await doTestAwait(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-  await doTestAwaitThen(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-  await doTestAwaitCatchError(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-
-  final asyncStarThrowSyncExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      asyncStarThrowSync \(.*/utils.dart:112(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      awaitEveryAsyncStarThrowSync \(.+\)$',
-  ];
-  await doTestAwait(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final asyncStarThrowAsyncExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      asyncStarThrowAsync \(.*/utils.dart:126(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      awaitEveryAsyncStarThrowAsync \(.+\)$',
-  ];
-  await doTestAwait(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final listenAsyncStartExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      asyncStarThrowAsync \(.*/utils.dart:126(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      listenAsyncStarThrowAsync \(.+/utils.dart:132(:27)?\)$',
-  ];
-  await doTestAwait(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final customErrorZoneExpected = const <String>[
-    r'#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'#1      allYield3 \(.*/utils.dart:39(:3)?\)$',
-    r'<asynchronous suspension>$',
-    r'#2      allYield2 \(.*/utils.dart:34(:9)?\)$',
-    r'<asynchronous suspension>$',
-    r'#3      allYield \(.*/utils.dart:29(:9)?\)$',
-    r'<asynchronous suspension>$',
-    r'#4      customErrorZone.<anonymous closure> \(.*/utils.dart:144(:11)?\)$',
-    r'#5      _rootRun ',
-    r'#6      _CustomZone.run ',
-    r'#7      _runZoned ',
-    r'#8      runZonedGuarded ',
-    r'#9      customErrorZone \(.*/utils.dart:143(:3)?\)$',
-  ];
-  await doTestAwait(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwait ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwaitThen ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwaitCatchError ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final awaitTimeoutExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      awaitTimeout ',
-  ];
-  await doTestAwait(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwait ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwaitThen ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwaitCatchError ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final awaitWaitExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      awaitWait ',
-  ];
-  await doTestAwait(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwait ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwaitThen ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwaitCatchError ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final futureSyncWhenCompleteExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      new Future.sync ',
-    r'^#2      futureSyncWhenComplete ',
-  ];
-  await doTestAwait(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwait ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-}
-
-// For: --no-causal-async-stacks --no-lazy-async-stacks
+// For: --no-lazy-async-stacks
 Future<void> doTestsNoCausalNoLazy([String? debugInfoFilename]) async {
   final allYieldExpected = const <String>[
     r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
diff --git a/runtime/tests/vm/dart/regress40189_test.dart b/runtime/tests/vm/dart/regress40189_test.dart
index 9f30e0c93fc..f857e5bc948 100644
--- a/runtime/tests/vm/dart/regress40189_test.dart
+++ b/runtime/tests/vm/dart/regress40189_test.dart
@@ -1,7 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import "package:expect/expect.dart";
 
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
index 2ec438e2cab..5f18af83c3e 100644
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
+++ b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_non_symbolic_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_lazy_debug.so --lazy-async-stacks --no-causal-async-stacks --no-use-bare-instructions
+//
+// VMOptions=--dwarf-stack-traces --save-debugging-info=async_lazy_debug.so --lazy-async-stacks --no-use-bare-instructions
 
 import 'dart:async';
 import 'dart:io';
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_test.dart
index 3155257b077..26805f15fa4 100644
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_test.dart
+++ b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_lazy_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'dart:async';
 
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
index f65de8494b8..c9dbb093dff 100644
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
+++ b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_non_symbolic_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_no_causal_debug.so --no-causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--dwarf-stack-traces --save-debugging-info=async_no_causal_debug.so --no-lazy-async-stacks
 
 import 'dart:async';
 import 'dart:io';
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_test.dart
index 7cc8cf0ee97..84848c943ab 100644
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_test.dart
+++ b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_no_causal_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--no-causal-async-stacks --no-lazy-async-stacks
+//
+// VMOptions=--no-lazy-async-stacks
 
 import 'dart:async';
 
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_non_symbolic_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_non_symbolic_test.dart
deleted file mode 100644
index cdb783a4104..00000000000
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_non_symbolic_test.dart
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--dwarf-stack-traces --save-debugging-info=async_causal_debug.so --causal-async-stacks --no-lazy-async-stacks
-
-import 'dart:async';
-import 'dart:io';
-
-import 'utils.dart';
-
-Future<void> main(List<String> args) async {
-  // We won't have access to the debugging info file on Android.
-  if (Platform.isAndroid) return;
-
-  await doTestsCausal('async_causal_debug.so');
-}
diff --git a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_test.dart b/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_test.dart
deleted file mode 100644
index 6d25d366615..00000000000
--- a/runtime/tests/vm/dart_2/causal_stacks/async_throws_stack_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
-
-import 'dart:async';
-
-import 'utils.dart';
-
-Future<void> main(List<String> args) async => await doTestsCausal();
diff --git a/runtime/tests/vm/dart_2/causal_stacks/utils.dart b/runtime/tests/vm/dart_2/causal_stacks/utils.dart
index f511d4cd920..192984fe79e 100644
--- a/runtime/tests/vm/dart_2/causal_stacks/utils.dart
+++ b/runtime/tests/vm/dart_2/causal_stacks/utils.dart
@@ -285,520 +285,7 @@ Future<void> doTestAwaitCatchError(Future f(), List<String> expectedStack,
 // Test "Suites":
 // ----
 
-// For: --causal-async-stacks
-Future<void> doTestsCausal([String debugInfoFilename]) async {
-  final allYieldExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      allYield3 \(.*/utils.dart:39(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      allYield2 \(.*/utils.dart:34(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      allYield \(.*/utils.dart:29(:9)?\)$',
-    r'^<asynchronous suspension>$',
-  ];
-  await doTestAwait(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      allYield,
-      allYieldExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final noYieldsExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      noYields3 \(.*/utils.dart:54(:3)?\)$',
-    r'^#2      noYields2 \(.*/utils.dart:50(:9)?\)$',
-    r'^#3      noYields \(.*/utils.dart:46(:9)?\)$',
-  ];
-  await doTestAwait(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      noYields,
-      noYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final mixedYieldsExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      mixedYields3 \(.*/utils.dart:70(:10)?\)$',
-    r'^#2      mixedYields2 \(.*/utils.dart:66(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      mixedYields \(.*/utils.dart:61(:9)?\)$',
-  ];
-  await doTestAwait(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      mixedYields,
-      mixedYieldsExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final syncSuffixExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      syncSuffix3 \(.*/utils.dart:86(:10)?\)$',
-    r'^#2      syncSuffix2 \(.*/utils.dart:82(:9)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#3      syncSuffix \(.*/utils.dart:77(:9)?\)$',
-  ];
-  await doTestAwait(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwait ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwaitThen ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      syncSuffix,
-      syncSuffixExpected +
-          const <String>[
-            r'^#4      doTestAwaitCatchError ',
-            r'^#5      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#6      main ',
-            r'^#7      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#8      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final nonAsyncNoStackExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      nonAsyncNoStack2.<anonymous closure> ',
-    r'^#2      _RootZone.runUnary ',
-    r'^#3      _FutureListener.handleValue ',
-    r'^#4      Future._propagateToListeners.handleValueCallback ',
-    r'^#5      Future._propagateToListeners ',
-    r'^#6      Future._completeWithValue ',
-    r'^#7      Future._asyncCompleteWithValue.<anonymous closure> ',
-    r'^#8      _microtaskLoop ',
-    r'^#9      _startMicrotaskLoop ',
-    r'^#10     _runPendingImmediateCallback ',
-    r'^#11     _RawReceivePortImpl._handleMessage ',
-  ];
-  await doTestAwait(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-  await doTestAwaitThen(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-  await doTestAwaitCatchError(
-      nonAsyncNoStack, nonAsyncNoStackExpected, debugInfoFilename);
-
-  final asyncStarThrowSyncExpected = const <String>[
-    r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'^#1      asyncStarThrowSync \(.*/utils.dart:112(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      awaitEveryAsyncStarThrowSync \(.+\)$',
-  ];
-  await doTestAwait(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitEveryAsyncStarThrowSync,
-      asyncStarThrowSyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final asyncStarThrowAsyncExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      asyncStarThrowAsync \(.*/utils.dart:126(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      awaitEveryAsyncStarThrowAsync \(.+\)$',
-  ];
-  await doTestAwait(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitEveryAsyncStarThrowAsync,
-      asyncStarThrowAsyncExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final listenAsyncStartExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      asyncStarThrowAsync \(.*/utils.dart:126(:11)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#2      listenAsyncStarThrowAsync \(.+/utils.dart:132(:27)?\)$',
-  ];
-  await doTestAwait(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwait \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      listenAsyncStarThrowAsync,
-      listenAsyncStartExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError \(.+\)$',
-            r'^#4      doTestsCausal \(.+\)$',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> \(.+\)$',
-            r'^#7      _RawReceivePortImpl._handleMessage \(.+\)$',
-          ],
-      debugInfoFilename);
-
-  final customErrorZoneExpected = const <String>[
-    r'#0      throwSync \(.*/utils.dart:16(:3)?\)$',
-    r'#1      allYield3 \(.*/utils.dart:39(:3)?\)$',
-    r'<asynchronous suspension>$',
-    r'#2      allYield2 \(.*/utils.dart:34(:9)?\)$',
-    r'<asynchronous suspension>$',
-    r'#3      allYield \(.*/utils.dart:29(:9)?\)$',
-    r'<asynchronous suspension>$',
-    r'#4      customErrorZone.<anonymous closure> \(.*/utils.dart:144(:11)?\)$',
-    r'#5      _rootRun ',
-    r'#6      _CustomZone.run ',
-    r'#7      _runZoned ',
-    r'#8      runZonedGuarded ',
-    r'#9      customErrorZone \(.*/utils.dart:143(:3)?\)$',
-  ];
-  await doTestAwait(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwait ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwaitThen ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      customErrorZone,
-      customErrorZoneExpected +
-          const <String>[
-            r'#10     doTestAwaitCatchError ',
-            r'#11     doTestsCausal ',
-            r'<asynchronous suspension>$',
-            r'#12     main \(.+\)$',
-            r'#13     _delayEntrypointInvocation.<anonymous closure> ',
-            r'#14     _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final awaitTimeoutExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      awaitTimeout ',
-  ];
-  await doTestAwait(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwait ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwaitThen ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitTimeout,
-      awaitTimeoutExpected +
-          const <String>[
-            r'^#2      doTestAwaitCatchError ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final awaitWaitExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      awaitWait ',
-  ];
-  await doTestAwait(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwait ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwaitThen ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      awaitWait,
-      awaitWaitExpected +
-          const <String>[
-            r'^#2      doTestAwaitCatchError ',
-            r'^#3      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#4      main \(.+\)$',
-            r'^#5      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#6      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-
-  final futureSyncWhenCompleteExpected = const <String>[
-    r'^#0      throwAsync \(.*/utils.dart:21(:3)?\)$',
-    r'^<asynchronous suspension>$',
-    r'^#1      new Future.sync ',
-    r'^#2      futureSyncWhenComplete ',
-  ];
-  await doTestAwait(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwait ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitThen(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwaitThen ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-  await doTestAwaitCatchError(
-      futureSyncWhenComplete,
-      futureSyncWhenCompleteExpected +
-          const <String>[
-            r'^#3      doTestAwaitCatchError ',
-            r'^#4      doTestsCausal ',
-            r'^<asynchronous suspension>$',
-            r'^#5      main \(.+\)$',
-            r'^#6      _delayEntrypointInvocation.<anonymous closure> ',
-            r'^#7      _RawReceivePortImpl._handleMessage ',
-          ],
-      debugInfoFilename);
-}
-
-// For: --no-causal-async-stacks --no-lazy-async-stacks
+// For: --no-lazy-async-stacks
 Future<void> doTestsNoCausalNoLazy([String debugInfoFilename]) async {
   final allYieldExpected = const <String>[
     r'^#0      throwSync \(.*/utils.dart:16(:3)?\)$',
diff --git a/runtime/tests/vm/dart_2/regress40189_test.dart b/runtime/tests/vm/dart_2/regress40189_test.dart
index 9f30e0c93fc..f857e5bc948 100644
--- a/runtime/tests/vm/dart_2/regress40189_test.dart
+++ b/runtime/tests/vm/dart_2/regress40189_test.dart
@@ -1,7 +1,8 @@
 // Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import "package:expect/expect.dart";
 
diff --git a/runtime/vm/BUILD.gn b/runtime/vm/BUILD.gn
index 1da3a20c1b4..49fac81fefd 100644
--- a/runtime/vm/BUILD.gn
+++ b/runtime/vm/BUILD.gn
@@ -178,10 +178,8 @@ template("gen_vm_platform") {
       "$root_out_dir/vm_outline" + output_postfix + ".dill",
     ]
     args = [ "dart:core" ]
-    allow_causal_async_stacks = false
     args += [
       "-Ddart.vm.product=$is_product_flag",
-      "-Ddart.developer.causal_async_stacks=$allow_causal_async_stacks",
       "-Ddart.isVM=true",
       "--enable-experiment=non-nullable",
       "--nnbd-agnostic",
diff --git a/runtime/vm/base_isolate.h b/runtime/vm/base_isolate.h
index be59b1667c8..a8c09eede1a 100644
--- a/runtime/vm/base_isolate.h
+++ b/runtime/vm/base_isolate.h
@@ -46,8 +46,6 @@ class BaseIsolate {
   // zones/handles in the API scope :
   // - Dart_RunLoop()
   // - IsolateSaver in Dart_NewNativePort
-  // Similarly, tracking async_stack_trace requires that we always reschedule
-  // on the same thread.
   // We probably need a mechanism to return to the specific thread only
   // for these specific cases. We should also determine if the embedder
   // should allow exiting an isolate with live state in zones/handles in
diff --git a/runtime/vm/bootstrap_natives.h b/runtime/vm/bootstrap_natives.h
index 8d51e7a3d62..b1e5e653c32 100644
--- a/runtime/vm/bootstrap_natives.h
+++ b/runtime/vm/bootstrap_natives.h
@@ -162,9 +162,6 @@ namespace dart {
   V(AssertionError_throwNew, 3)                                                \
   V(AssertionError_throwNewSource, 4)                                          \
   V(Async_rethrow, 2)                                                          \
-  V(StackTrace_asyncStackTraceHelper, 1)                                       \
-  V(StackTrace_clearAsyncThreadStackTrace, 0)                                  \
-  V(StackTrace_setAsyncThreadStackTrace, 1)                                    \
   V(StackTrace_current, 0)                                                     \
   V(TypeError_throwNew, 4)                                                     \
   V(FallThroughError_throwNew, 1)                                              \
diff --git a/runtime/vm/compilation_trace.cc b/runtime/vm/compilation_trace.cc
index 5a8636637ee..d2f88ed1fec 100644
--- a/runtime/vm/compilation_trace.cc
+++ b/runtime/vm/compilation_trace.cc
@@ -448,7 +448,6 @@ static char* CompilerFlags() {
   ADD_FLAG(enable_asserts);
   ADD_FLAG(use_field_guards);
   ADD_FLAG(use_osr);
-  ADD_FLAG(causal_async_stacks);
   ADD_FLAG(fields_may_be_reset);
 #undef ADD_FLAG
 
diff --git a/runtime/vm/compiler/aot/precompiler.cc b/runtime/vm/compiler/aot/precompiler.cc
index 592f55fd7d0..ea2fc4a5a0a 100644
--- a/runtime/vm/compiler/aot/precompiler.cc
+++ b/runtime/vm/compiler/aot/precompiler.cc
@@ -416,7 +416,6 @@ void Precompiler::DoCompileAll() {
       I->object_store()->set_simple_instance_of_function(null_function);
       I->object_store()->set_simple_instance_of_true_function(null_function);
       I->object_store()->set_simple_instance_of_false_function(null_function);
-      I->object_store()->set_async_set_thread_stack_trace(null_function);
       I->object_store()->set_async_star_move_next_helper(null_function);
       I->object_store()->set_complete_on_async_return(null_function);
       I->object_store()->set_async_star_stream_controller(null_class);
diff --git a/runtime/vm/compiler/asm_intrinsifier_arm.cc b/runtime/vm/compiler/asm_intrinsifier_arm.cc
index 9a58b9e81dd..fd9c7c7739a 100644
--- a/runtime/vm/compiler/asm_intrinsifier_arm.cc
+++ b/runtime/vm/compiler/asm_intrinsifier_arm.cc
@@ -2235,20 +2235,6 @@ void AsmIntrinsifier::Timeline_isDartStreamEnabled(Assembler* assembler,
 #endif
 }
 
-void AsmIntrinsifier::ClearAsyncThreadStackTrace(Assembler* assembler,
-                                                 Label* normal_ir_body) {
-  __ LoadObject(R0, NullObject());
-  __ str(R0, Address(THR, target::Thread::async_stack_trace_offset()));
-  __ Ret();
-}
-
-void AsmIntrinsifier::SetAsyncThreadStackTrace(Assembler* assembler,
-                                               Label* normal_ir_body) {
-  __ ldr(R0, Address(THR, target::Thread::async_stack_trace_offset()));
-  __ LoadObject(R0, NullObject());
-  __ Ret();
-}
-
 #undef __
 
 }  // namespace compiler
diff --git a/runtime/vm/compiler/asm_intrinsifier_arm64.cc b/runtime/vm/compiler/asm_intrinsifier_arm64.cc
index 6464f77afcb..1c1271d5063 100644
--- a/runtime/vm/compiler/asm_intrinsifier_arm64.cc
+++ b/runtime/vm/compiler/asm_intrinsifier_arm64.cc
@@ -2332,20 +2332,6 @@ void AsmIntrinsifier::Timeline_isDartStreamEnabled(Assembler* assembler,
 #endif
 }
 
-void AsmIntrinsifier::ClearAsyncThreadStackTrace(Assembler* assembler,
-                                                 Label* normal_ir_body) {
-  __ LoadObject(R0, NullObject());
-  __ str(R0, Address(THR, target::Thread::async_stack_trace_offset()));
-  __ ret();
-}
-
-void AsmIntrinsifier::SetAsyncThreadStackTrace(Assembler* assembler,
-                                               Label* normal_ir_body) {
-  __ ldr(R0, Address(THR, target::Thread::async_stack_trace_offset()));
-  __ LoadObject(R0, NullObject());
-  __ ret();
-}
-
 #undef __
 
 }  // namespace compiler
diff --git a/runtime/vm/compiler/asm_intrinsifier_ia32.cc b/runtime/vm/compiler/asm_intrinsifier_ia32.cc
index 09a12de5841..ec97c642da6 100644
--- a/runtime/vm/compiler/asm_intrinsifier_ia32.cc
+++ b/runtime/vm/compiler/asm_intrinsifier_ia32.cc
@@ -2240,20 +2240,6 @@ void AsmIntrinsifier::Timeline_isDartStreamEnabled(Assembler* assembler,
 #endif
 }
 
-void AsmIntrinsifier::ClearAsyncThreadStackTrace(Assembler* assembler,
-                                                 Label* normal_ir_body) {
-  __ LoadObject(EAX, NullObject());
-  __ movl(Address(THR, target::Thread::async_stack_trace_offset()), EAX);
-  __ ret();
-}
-
-void AsmIntrinsifier::SetAsyncThreadStackTrace(Assembler* assembler,
-                                               Label* normal_ir_body) {
-  __ movl(Address(THR, target::Thread::async_stack_trace_offset()), EAX);
-  __ LoadObject(EAX, NullObject());
-  __ ret();
-}
-
 #undef __
 
 }  // namespace compiler
diff --git a/runtime/vm/compiler/asm_intrinsifier_x64.cc b/runtime/vm/compiler/asm_intrinsifier_x64.cc
index dad953a920b..8a424dd8cb4 100644
--- a/runtime/vm/compiler/asm_intrinsifier_x64.cc
+++ b/runtime/vm/compiler/asm_intrinsifier_x64.cc
@@ -2268,20 +2268,6 @@ void AsmIntrinsifier::Timeline_isDartStreamEnabled(Assembler* assembler,
 #endif
 }
 
-void AsmIntrinsifier::ClearAsyncThreadStackTrace(Assembler* assembler,
-                                                 Label* normal_ir_body) {
-  __ LoadObject(RAX, NullObject());
-  __ movq(Address(THR, target::Thread::async_stack_trace_offset()), RAX);
-  __ ret();
-}
-
-void AsmIntrinsifier::SetAsyncThreadStackTrace(Assembler* assembler,
-                                               Label* normal_ir_body) {
-  __ movq(Address(THR, target::Thread::async_stack_trace_offset()), RAX);
-  __ LoadObject(RAX, NullObject());
-  __ ret();
-}
-
 #undef __
 
 }  // namespace compiler
diff --git a/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc b/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
index 397daafc8ff..83f434f6b8c 100644
--- a/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
+++ b/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc
@@ -482,40 +482,6 @@ Fragment StreamingFlowGraphBuilder::DebugStepCheckInPrologue(
   return DebugStepCheck(check_pos);
 }
 
-Fragment StreamingFlowGraphBuilder::SetAsyncStackTrace(
-    const Function& dart_function) {
-  if (!FLAG_causal_async_stacks ||
-      !(dart_function.IsAsyncClosure() || dart_function.IsAsyncGenClosure())) {
-    return {};
-  }
-
-  // The code we are building will be executed right after we enter
-  // the function and before any nested contexts are allocated.
-  ASSERT(B->context_depth_ ==
-         scopes()->yield_jump_variable->owner()->context_level());
-
-  Fragment instructions;
-  LocalScope* scope = parsed_function()->scope();
-
-  const Function& target = Function::ZoneHandle(
-      Z, I->object_store()->async_set_thread_stack_trace());
-  ASSERT(!target.IsNull());
-
-  // Fetch and load :async_stack_trace
-  LocalVariable* async_stack_trace_var =
-      scope->LookupVariable(Symbols::AsyncStackTraceVar(), false);
-  ASSERT((async_stack_trace_var != NULL) &&
-         async_stack_trace_var->is_captured());
-
-  Fragment code;
-  code += LoadLocal(async_stack_trace_var);
-  // Call _setAsyncThreadStackTrace
-  code += StaticCall(TokenPosition::kNoSource, target,
-                     /* argument_count = */ 1, ICData::kStatic);
-  code += Drop();
-  return code;
-}
-
 Fragment StreamingFlowGraphBuilder::TypeArgumentsHandling(
     const Function& dart_function) {
   Fragment prologue = B->BuildDefaultTypeHandling(dart_function);
@@ -801,7 +767,6 @@ Fragment StreamingFlowGraphBuilder::BuildEveryTimePrologue(
   Fragment F;
   F += CheckStackOverflowInPrologue(dart_function);
   F += DebugStepCheckInPrologue(dart_function, token_position);
-  F += SetAsyncStackTrace(dart_function);
   F += B->InitConstantParameters();
   return F;
 }
@@ -3042,10 +3007,6 @@ Fragment StreamingFlowGraphBuilder::BuildStaticInvocation(TokenPosition* p) {
   Fragment instructions;
   LocalVariable* instance_variable = NULL;
 
-  const bool special_case_nop_async_stack_trace_helper =
-      !FLAG_causal_async_stacks &&
-      recognized_kind == MethodRecognizer::kAsyncStackTraceHelper;
-
   const bool special_case_unchecked_cast =
       klass.IsTopLevel() && (klass.library() == Library::InternalLibrary()) &&
       (target.name() == Symbols::UnsafeCast().raw());
@@ -3054,9 +3015,8 @@ Fragment StreamingFlowGraphBuilder::BuildStaticInvocation(TokenPosition* p) {
       klass.IsTopLevel() && (klass.library() == Library::CoreLibrary()) &&
       (target.name() == Symbols::Identical().raw());
 
-  const bool special_case = special_case_identical ||
-                            special_case_unchecked_cast ||
-                            special_case_nop_async_stack_trace_helper;
+  const bool special_case =
+      special_case_identical || special_case_unchecked_cast;
 
   // If we cross the Kernel -> VM core library boundary, a [StaticInvocation]
   // can appear, but the thing we're calling is not a static method, but a
@@ -3116,10 +3076,6 @@ Fragment StreamingFlowGraphBuilder::BuildStaticInvocation(TokenPosition* p) {
     ASSERT(argument_count == 2);
     instructions +=
         StrictCompare(position, Token::kEQ_STRICT, /*number_check=*/true);
-  } else if (special_case_nop_async_stack_trace_helper) {
-    ASSERT(argument_count == 1);
-    instructions += Drop();
-    instructions += NullConstant();
   } else if (special_case_unchecked_cast) {
     // Simply do nothing: the result value is already pushed on the stack.
   } else {
diff --git a/runtime/vm/compiler/frontend/kernel_to_il.cc b/runtime/vm/compiler/frontend/kernel_to_il.cc
index f7327ba4b9c..1620bbf200a 100644
--- a/runtime/vm/compiler/frontend/kernel_to_il.cc
+++ b/runtime/vm/compiler/frontend/kernel_to_il.cc
@@ -546,18 +546,6 @@ Fragment FlowGraphBuilder::Return(TokenPosition position,
     instructions += DebugStepCheck(position);
   }
 
-  if (FLAG_causal_async_stacks &&
-      (function.IsAsyncClosure() || function.IsAsyncGenClosure())) {
-    // We are returning from an asynchronous closure. Before we do that, be
-    // sure to clear the thread's asynchronous stack trace.
-    const Function& target = Function::ZoneHandle(
-        Z, I->object_store()->async_clear_thread_stack_trace());
-    ASSERT(!target.IsNull());
-    instructions += StaticCall(TokenPosition::kNoSource, target,
-                               /* argument_count = */ 0, ICData::kStatic);
-    instructions += Drop();
-  }
-
   instructions += BaseFlowGraphBuilder::Return(position, yield_index);
 
   return instructions;
@@ -880,8 +868,6 @@ bool FlowGraphBuilder::IsRecognizedMethodForFlowGraph(
     case MethodRecognizer::kReachabilityFence:
     case MethodRecognizer::kUtf8DecoderScan:
       return true;
-    case MethodRecognizer::kAsyncStackTraceHelper:
-      return !FLAG_causal_async_stacks;
     default:
       return false;
   }
@@ -1225,10 +1211,6 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfRecognizedMethod(
           StoreInstanceFieldInstr::Kind::kOther, kNoStoreBarrier);
       body += NullConstant();
       break;
-    case MethodRecognizer::kAsyncStackTraceHelper:
-      ASSERT(!FLAG_causal_async_stacks);
-      body += NullConstant();
-      break;
     case MethodRecognizer::kUtf8DecoderScan:
       ASSERT(function.NumParameters() == 5);
       body += LoadLocal(parsed_function_->RawParameterVariable(0));  // decoder
diff --git a/runtime/vm/compiler/frontend/scope_builder.cc b/runtime/vm/compiler/frontend/scope_builder.cc
index ab4762ad0a0..8ca008eb96d 100644
--- a/runtime/vm/compiler/frontend/scope_builder.cc
+++ b/runtime/vm/compiler/frontend/scope_builder.cc
@@ -550,16 +550,6 @@ void ScopeBuilder::VisitFunctionNode() {
   }
   function_node_helper.SetJustRead(FunctionNodeHelper::kTypeParameters);
 
-  if (FLAG_causal_async_stacks &&
-      (function_node_helper.dart_async_marker_ == FunctionNodeHelper::kAsync ||
-       function_node_helper.dart_async_marker_ ==
-           FunctionNodeHelper::kAsyncStar)) {
-    LocalVariable* asyncStackTraceVar = MakeVariable(
-        TokenPosition::kNoSource, TokenPosition::kNoSource,
-        Symbols::AsyncStackTraceVar(), AbstractType::dynamic_type());
-    scope_->AddVariable(asyncStackTraceVar);
-  }
-
   // The :sync_op and :async_op continuations are called multiple times. So we
   // don't want the parameters from the first invocation to get stored in the
   // context and reused on later invocations with different parameters.
@@ -579,8 +569,8 @@ void ScopeBuilder::VisitFunctionNode() {
     first_body_token_position_ = helper_.reader_.min_position();
   }
 
-  // Ensure that :await_jump_var, :await_ctx_var, :async_op, :is_sync,
-  // :async_future and :async_stack_trace are captured.
+  // Ensure that :await_jump_var, :await_ctx_var, :async_op, :is_sync and
+  // :async_future are captured.
   if (function_node_helper.async_marker_ == FunctionNodeHelper::kSyncYielding) {
     {
       LocalVariable* temp = nullptr;
@@ -621,13 +611,6 @@ void ScopeBuilder::VisitFunctionNode() {
         scope_->CaptureVariable(temp);
       }
     }
-    if (FLAG_causal_async_stacks) {
-      LocalVariable* temp =
-          scope_->LookupVariable(Symbols::AsyncStackTraceVar(), true);
-      if (temp != nullptr) {
-        scope_->CaptureVariable(temp);
-      }
-    }
   }
 
   // Mark known chained futures such as _Future::timeout()'s _future.
diff --git a/runtime/vm/compiler/jit/compiler.cc b/runtime/vm/compiler/jit/compiler.cc
index 571907e54fa..2c54ec69480 100644
--- a/runtime/vm/compiler/jit/compiler.cc
+++ b/runtime/vm/compiler/jit/compiler.cc
@@ -104,7 +104,6 @@ static void PrecompilationModeHandler(bool value) {
     FLAG_reorder_basic_blocks = true;
     FLAG_use_field_guards = false;
     FLAG_use_cha_deopt = false;
-    FLAG_causal_async_stacks = false;
     FLAG_lazy_async_stacks = true;
 
 #if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
diff --git a/runtime/vm/compiler/recognized_methods_list.h b/runtime/vm/compiler/recognized_methods_list.h
index 1f50840a014..1323840498a 100644
--- a/runtime/vm/compiler/recognized_methods_list.h
+++ b/runtime/vm/compiler/recognized_methods_list.h
@@ -159,7 +159,6 @@ namespace dart {
   V(_HashVMBase, get:_deletedKeys, LinkedHashMap_getDeletedKeys, 0xd55a64fe)   \
   V(_HashVMBase, set:_deletedKeys, LinkedHashMap_setDeletedKeys, 0x5570ec7a)   \
   V(::, _classRangeCheck, ClassRangeCheck, 0x5ee76890)                         \
-  V(::, _asyncStackTraceHelper, AsyncStackTraceHelper, 0x92cea93f)             \
   V(::, _abi, FfiAbi, 0x00a48df9)                                              \
   V(::, _asFunctionInternal, FfiAsFunctionInternal, 0x4ea3f680)                \
   V(::, _nativeCallbackFunction, FfiNativeCallbackFunction, 0xe7a60d02)        \
@@ -383,10 +382,6 @@ namespace dart {
   V(::, _getCurrentTag, Profiler_getCurrentTag, 0x33c3ec34)                    \
   V(::, _isDartStreamEnabled, Timeline_isDartStreamEnabled, 0x7dfcaa37)        \
 
-#define ASYNC_LIB_INTRINSIC_LIST(V)                                            \
-  V(::, _clearAsyncThreadStackTrace, ClearAsyncThreadStackTrace, 0x20fecae5)   \
-  V(::, _setAsyncThreadStackTrace, SetAsyncThreadStackTrace, 0x39346972)       \
-
 #define INTERNAL_LIB_INTRINSIC_LIST(V)                                         \
   V(::, allocateOneByteString, AllocateOneByteString, 0xc86bebfa)              \
   V(::, allocateTwoByteString, AllocateTwoByteString, 0xd0312797)              \
@@ -394,7 +389,6 @@ namespace dart {
   V(::, writeIntoTwoByteString, WriteIntoTwoByteString, 0xd82789d0)            \
 
 #define ALL_INTRINSICS_NO_INTEGER_LIB_LIST(V)                                  \
-  ASYNC_LIB_INTRINSIC_LIST(V)                                                  \
   CORE_LIB_INTRINSIC_LIST(V)                                                   \
   DEVELOPER_LIB_INTRINSIC_LIST(V)                                              \
   INTERNAL_LIB_INTRINSIC_LIST(V)                                               \
diff --git a/runtime/vm/compiler/runtime_api.h b/runtime/vm/compiler/runtime_api.h
index 4418eebc47e..7ab2fdd9668 100644
--- a/runtime/vm/compiler/runtime_api.h
+++ b/runtime/vm/compiler/runtime_api.h
@@ -990,7 +990,6 @@ class Thread : public AllStatic {
   static uword exit_through_runtime_call();
   static uword exit_through_ffi();
   static word dart_stream_offset();
-  static word async_stack_trace_offset();
   static word predefined_symbols_address_offset();
   static word optimize_entry_offset();
   static word deoptimize_entry_offset();
diff --git a/runtime/vm/compiler/runtime_offsets_extracted.h b/runtime/vm/compiler/runtime_offsets_extracted.h
index f1f6fa3a529..e4dae18c5d0 100644
--- a/runtime/vm/compiler/runtime_offsets_extracted.h
+++ b/runtime/vm/compiler/runtime_offsets_extracted.h
@@ -219,155 +219,153 @@ static constexpr dart::compiler::target::word String_hash_offset = 8;
 static constexpr dart::compiler::target::word String_length_offset = 4;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 376;
+    Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    700;
+    692;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 128;
+    Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 272;
+    Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 288;
+    Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 196;
+    Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 292;
+    Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 200;
+    Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 296;
+    Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 204;
-static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 732;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    96;
+    Thread_allocate_object_slow_stub_offset = 196;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 724;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 340;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 120;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 116;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 332;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 112;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 276;
+    Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 144;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 740;
+    Thread_call_to_runtime_stub_offset = 136;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 732;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    316;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 232;
+    308;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 224;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    320;
+    312;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    236;
+    228;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    356;
+    348;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 352;
+    Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 256;
+    Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    716;
+    708;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 260;
+    Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 264;
+    Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 324;
+    Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 136;
+    Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 132;
+    Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 368;
+    Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 364;
+    Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    360;
+    352;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 372;
+    Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 140;
+    Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    728;
+    720;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     68;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 240;
+    Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 244;
+    Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 252;
+    Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 308;
+    Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 312;
+    Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 216;
+    Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 148;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 140;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 112;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 104;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 708;
+    Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 700;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 712;
+    Thread_saved_shadow_call_stack_offset = 704;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    720;
+    712;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 248;
+    Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 328;
+    Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 36;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     60;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     80;
 static constexpr dart::compiler::target::word
@@ -375,15 +373,15 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 52;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 24;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 104;
+    Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    124;
+    116;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 268;
+    Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     40;
-static constexpr dart::compiler::target::word Thread_callback_code_offset = 724;
+static constexpr dart::compiler::target::word Thread_callback_code_offset = 716;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Type_arguments_offset = 16;
@@ -435,7 +433,7 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     4, 12, 8, 16};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        664, 668, 672, 676, 680, -1, 684, -1, 688, 692, -1, -1, -1, -1, -1, -1};
+        656, 660, 664, 668, 672, -1, 676, -1, 680, 684, -1, -1, -1, -1, -1, -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
 static constexpr dart::compiler::target::word Array_InstanceSize = 12;
 static constexpr dart::compiler::target::word Array_header_size = 12;
@@ -738,156 +736,154 @@ static constexpr dart::compiler::target::word String_hash_offset = 4;
 static constexpr dart::compiler::target::word String_length_offset = 8;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 736;
+    Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    1400;
+    1392;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    1408;
+    1400;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 240;
+    Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 528;
+    Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 560;
+    Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 376;
+    Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 568;
+    Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 384;
+    Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 576;
+    Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 392;
+    Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
-    1472;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    192;
+    1464;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 664;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 224;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 216;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 656;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 216;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 536;
+    Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 272;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1488;
+    Thread_call_to_runtime_stub_offset = 264;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1480;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    616;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 448;
+    608;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 440;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    624;
+    616;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    456;
+    448;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 688;
+    Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 496;
+    Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    1440;
+    1432;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 504;
+    Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 512;
+    Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 632;
+    Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 256;
+    Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 248;
+    Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 720;
+    Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 712;
+    Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 728;
+    Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    1416;
+    1408;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 264;
+    Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    1464;
+    1456;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     136;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 464;
+    Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 472;
+    Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 488;
+    Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 600;
+    Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 608;
+    Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 416;
+    Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 280;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 208;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 200;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 672;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1424;
+    Thread_predefined_symbols_address_offset = 664;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1416;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 1432;
+    Thread_saved_shadow_call_stack_offset = 1424;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    1448;
+    1440;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 480;
+    Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 640;
+    Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 72;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     120;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     160;
 static constexpr dart::compiler::target::word
@@ -895,16 +891,16 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 104;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 48;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 200;
+    Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 520;
+    Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     80;
 static constexpr dart::compiler::target::word Thread_callback_code_offset =
-    1456;
+    1448;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
     16;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
@@ -957,8 +953,8 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, -1,   -1,   1344, 1352,
-        1360, 1368, 1376, -1,   1384, 1392, -1,   -1};
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word Array_header_size = 24;
@@ -1259,155 +1255,153 @@ static constexpr dart::compiler::target::word String_hash_offset = 8;
 static constexpr dart::compiler::target::word String_length_offset = 4;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 376;
+    Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    664;
+    656;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    668;
+    660;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 128;
+    Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 272;
+    Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 288;
+    Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 196;
+    Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 292;
+    Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 200;
+    Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 296;
+    Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 204;
-static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 700;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    96;
+    Thread_allocate_object_slow_stub_offset = 196;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 692;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 340;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 120;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 116;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 332;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 112;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 276;
+    Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 144;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 708;
+    Thread_call_to_runtime_stub_offset = 136;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 700;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    316;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 232;
+    308;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 224;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    320;
+    312;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    236;
+    228;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    356;
+    348;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 352;
+    Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 256;
+    Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    684;
+    676;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 260;
+    Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 264;
+    Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 324;
+    Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 136;
+    Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 132;
+    Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 368;
+    Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 364;
+    Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    360;
+    352;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 372;
+    Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    672;
+    664;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 140;
+    Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     68;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 240;
+    Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 244;
+    Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 252;
+    Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 308;
+    Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 312;
+    Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 216;
+    Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 148;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 140;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 112;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 104;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 676;
+    Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 668;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 680;
+    Thread_saved_shadow_call_stack_offset = 672;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    688;
+    680;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 248;
+    Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 328;
+    Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 36;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     60;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     80;
 static constexpr dart::compiler::target::word
@@ -1415,15 +1409,15 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 52;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 24;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 104;
+    Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    124;
+    116;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 268;
+    Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     40;
-static constexpr dart::compiler::target::word Thread_callback_code_offset = 692;
+static constexpr dart::compiler::target::word Thread_callback_code_offset = 684;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Type_arguments_offset = 16;
@@ -1775,156 +1769,154 @@ static constexpr dart::compiler::target::word String_hash_offset = 4;
 static constexpr dart::compiler::target::word String_length_offset = 8;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 736;
+    Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    1472;
+    1464;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    1480;
+    1472;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 240;
+    Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 528;
+    Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 560;
+    Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 376;
+    Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 568;
+    Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 384;
+    Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 576;
+    Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 392;
+    Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
-    1544;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    192;
+    1536;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 664;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 224;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 216;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 656;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 216;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 536;
+    Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 272;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1560;
+    Thread_call_to_runtime_stub_offset = 264;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1552;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    616;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 448;
+    608;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 440;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    624;
+    616;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    456;
+    448;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 688;
+    Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 496;
+    Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    1512;
+    1504;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 504;
+    Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 512;
+    Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 632;
+    Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 256;
+    Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 248;
+    Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 720;
+    Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 712;
+    Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 728;
+    Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    1488;
+    1480;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 264;
+    Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    1536;
+    1528;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     136;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 464;
+    Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 472;
+    Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 488;
+    Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 600;
+    Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 608;
+    Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 416;
+    Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 280;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 208;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 200;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 672;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1496;
+    Thread_predefined_symbols_address_offset = 664;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1488;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 1504;
+    Thread_saved_shadow_call_stack_offset = 1496;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    1520;
+    1512;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 480;
+    Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 640;
+    Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 72;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     120;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     160;
 static constexpr dart::compiler::target::word
@@ -1932,16 +1924,16 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 104;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 48;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 200;
+    Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 520;
+    Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     80;
 static constexpr dart::compiler::target::word Thread_callback_code_offset =
-    1528;
+    1520;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
     16;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
@@ -1994,9 +1986,9 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384, 1392,
-        1400, 1408, 1416, 1424, -1,   -1,   -1,   -1,   1432, 1440, -1,
-        -1,   1448, 1456, 1464, -1,   -1,   -1,   -1,   -1,   -1};
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word Array_header_size = 24;
@@ -2296,155 +2288,153 @@ static constexpr dart::compiler::target::word String_hash_offset = 8;
 static constexpr dart::compiler::target::word String_length_offset = 4;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 376;
+    Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    700;
+    692;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 128;
+    Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 272;
+    Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 288;
+    Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 196;
+    Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 292;
+    Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 200;
+    Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 296;
+    Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 204;
-static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 732;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    96;
+    Thread_allocate_object_slow_stub_offset = 196;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 724;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 340;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 120;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 116;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 332;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 112;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 276;
+    Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 144;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 740;
+    Thread_call_to_runtime_stub_offset = 136;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 732;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    316;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 232;
+    308;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 224;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    320;
+    312;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    236;
+    228;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    356;
+    348;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 352;
+    Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 256;
+    Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    716;
+    708;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 260;
+    Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 264;
+    Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 324;
+    Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 136;
+    Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 132;
+    Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 368;
+    Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 364;
+    Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    360;
+    352;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 372;
+    Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 140;
+    Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    728;
+    720;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     68;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 240;
+    Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 244;
+    Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 252;
+    Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 308;
+    Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 312;
+    Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 216;
+    Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 148;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 140;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 112;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 104;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 708;
+    Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 700;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 712;
+    Thread_saved_shadow_call_stack_offset = 704;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    720;
+    712;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 248;
+    Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 328;
+    Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 36;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     60;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     80;
 static constexpr dart::compiler::target::word
@@ -2452,15 +2442,15 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 52;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 24;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 104;
+    Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    124;
+    116;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 268;
+    Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     40;
-static constexpr dart::compiler::target::word Thread_callback_code_offset = 724;
+static constexpr dart::compiler::target::word Thread_callback_code_offset = 716;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Type_arguments_offset = 16;
@@ -2509,7 +2499,7 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     4, 12, 8, 16};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        664, 668, 672, 676, 680, -1, 684, -1, 688, 692, -1, -1, -1, -1, -1, -1};
+        656, 660, 664, 668, 672, -1, 676, -1, 680, 684, -1, -1, -1, -1, -1, -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 8;
 static constexpr dart::compiler::target::word Array_InstanceSize = 12;
 static constexpr dart::compiler::target::word Array_header_size = 12;
@@ -2809,156 +2799,154 @@ static constexpr dart::compiler::target::word String_hash_offset = 4;
 static constexpr dart::compiler::target::word String_length_offset = 8;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 736;
+    Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    1400;
+    1392;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    1408;
+    1400;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 240;
+    Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 528;
+    Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 560;
+    Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 376;
+    Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 568;
+    Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 384;
+    Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 576;
+    Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 392;
+    Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
-    1472;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    192;
+    1464;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 664;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 224;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 216;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 656;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 216;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 536;
+    Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 272;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1488;
+    Thread_call_to_runtime_stub_offset = 264;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1480;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    616;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 448;
+    608;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 440;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    624;
+    616;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    456;
+    448;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 688;
+    Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 496;
+    Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    1440;
+    1432;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 504;
+    Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 512;
+    Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 632;
+    Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 256;
+    Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 248;
+    Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 720;
+    Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 712;
+    Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 728;
+    Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    1416;
+    1408;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 264;
+    Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    1464;
+    1456;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     136;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 464;
+    Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 472;
+    Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 488;
+    Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 600;
+    Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 608;
+    Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 416;
+    Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 280;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 208;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 200;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 672;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1424;
+    Thread_predefined_symbols_address_offset = 664;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1416;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 1432;
+    Thread_saved_shadow_call_stack_offset = 1424;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    1448;
+    1440;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 480;
+    Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 640;
+    Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 72;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     120;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     160;
 static constexpr dart::compiler::target::word
@@ -2966,16 +2954,16 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 104;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 48;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 200;
+    Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 520;
+    Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     80;
 static constexpr dart::compiler::target::word Thread_callback_code_offset =
-    1456;
+    1448;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
     16;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
@@ -3025,8 +3013,8 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, -1,   -1,   1344, 1352,
-        1360, 1368, 1376, -1,   1384, 1392, -1,   -1};
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word Array_header_size = 24;
@@ -3324,155 +3312,153 @@ static constexpr dart::compiler::target::word String_hash_offset = 8;
 static constexpr dart::compiler::target::word String_length_offset = 4;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 376;
+    Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    664;
+    656;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    668;
+    660;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 128;
+    Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 272;
+    Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 288;
+    Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 196;
+    Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 292;
+    Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 200;
+    Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 296;
+    Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 204;
-static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 700;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    96;
+    Thread_allocate_object_slow_stub_offset = 196;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset = 692;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 340;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 120;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 116;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 332;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 112;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 276;
+    Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 144;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 708;
+    Thread_call_to_runtime_stub_offset = 136;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 700;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    316;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 232;
+    308;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 224;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    320;
+    312;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    236;
+    228;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    356;
+    348;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 352;
+    Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 256;
+    Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    684;
+    676;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 260;
+    Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 264;
+    Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 324;
+    Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 136;
+    Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 132;
+    Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 368;
+    Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 364;
+    Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    360;
+    352;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 372;
+    Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    672;
+    664;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 140;
+    Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     68;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 240;
+    Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 244;
+    Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 252;
+    Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 308;
+    Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 312;
+    Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 216;
+    Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 148;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 140;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 112;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 104;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 676;
+    Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 668;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 680;
+    Thread_saved_shadow_call_stack_offset = 672;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    688;
+    680;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 248;
+    Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 328;
+    Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 36;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     60;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     80;
 static constexpr dart::compiler::target::word
@@ -3480,15 +3466,15 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 52;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 24;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 104;
+    Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    124;
+    116;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 268;
+    Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     40;
-static constexpr dart::compiler::target::word Thread_callback_code_offset = 692;
+static constexpr dart::compiler::target::word Thread_callback_code_offset = 684;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 12;
 static constexpr dart::compiler::target::word Type_arguments_offset = 16;
@@ -3834,156 +3820,154 @@ static constexpr dart::compiler::target::word String_hash_offset = 4;
 static constexpr dart::compiler::target::word String_length_offset = 8;
 static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    Thread_AllocateArray_entry_point_offset = 736;
+    Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word Thread_active_exception_offset =
-    1472;
+    1464;
 static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
-    1480;
+    1472;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_code_offset = 240;
+    Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    Thread_array_write_barrier_entry_point_offset = 528;
+    Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_entry_point_offset = 560;
+    Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_stub_offset = 376;
+    Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_entry_point_offset = 568;
+    Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_parameterized_stub_offset = 384;
+    Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_entry_point_offset = 576;
+    Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    Thread_allocate_object_slow_stub_offset = 392;
+    Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
-    1544;
-static constexpr dart::compiler::target::word Thread_async_stack_trace_offset =
-    192;
+    1536;
 static constexpr dart::compiler::target::word
-    Thread_auto_scope_native_wrapper_entry_point_offset = 664;
-static constexpr dart::compiler::target::word Thread_bool_false_offset = 224;
-static constexpr dart::compiler::target::word Thread_bool_true_offset = 216;
+    Thread_auto_scope_native_wrapper_entry_point_offset = 656;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 216;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_entry_point_offset = 536;
+    Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    Thread_call_to_runtime_stub_offset = 272;
-static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1560;
+    Thread_call_to_runtime_stub_offset = 264;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1552;
 static constexpr dart::compiler::target::word
     Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
-    616;
-static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 448;
+    608;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 440;
 static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
-    624;
+    616;
 static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
-    456;
+    448;
 static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
-    696;
+    688;
 static constexpr dart::compiler::target::word
-    Thread_double_negate_address_offset = 688;
+    Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    Thread_enter_safepoint_stub_offset = 496;
+    Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word Thread_execution_state_offset =
-    1512;
+    1504;
 static constexpr dart::compiler::target::word
-    Thread_exit_safepoint_stub_offset = 504;
+    Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_stub_offset = 512;
+    Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    Thread_call_native_through_safepoint_entry_point_offset = 632;
+    Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    Thread_fix_allocation_stub_code_offset = 256;
+    Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    Thread_fix_callers_target_code_offset = 248;
+    Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    Thread_float_absolute_address_offset = 720;
+    Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    Thread_float_negate_address_offset = 712;
+    Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word Thread_float_not_address_offset =
-    704;
+    696;
 static constexpr dart::compiler::target::word
-    Thread_float_zerow_address_offset = 728;
+    Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
-    1488;
+    1480;
 static constexpr dart::compiler::target::word
-    Thread_invoke_dart_code_stub_offset = 264;
+    Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
-    1536;
+    1528;
 static constexpr dart::compiler::target::word Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word Thread_field_table_values_offset =
     136;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_return_stub_offset = 464;
+    Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    Thread_lazy_deopt_from_throw_stub_offset = 472;
+    Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    Thread_lazy_specialize_type_test_stub_offset = 488;
+    Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    Thread_megamorphic_call_checked_entry_offset = 600;
+    Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_entry_offset = 608;
+    Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    Thread_switchable_call_miss_stub_offset = 416;
+    Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
-    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 280;
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 272;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
-static constexpr dart::compiler::target::word Thread_object_null_offset = 208;
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 200;
 static constexpr dart::compiler::target::word
-    Thread_predefined_symbols_address_offset = 672;
-static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1496;
+    Thread_predefined_symbols_address_offset = 664;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1488;
 static constexpr dart::compiler::target::word
-    Thread_saved_shadow_call_stack_offset = 1504;
+    Thread_saved_shadow_call_stack_offset = 1496;
 static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
-    1520;
+    1512;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_stub_offset = 480;
+    Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    Thread_slow_type_test_entry_point_offset = 640;
+    Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word Thread_stack_limit_offset = 72;
 static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
     120;
 static constexpr dart::compiler::target::word
     Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
     160;
 static constexpr dart::compiler::target::word
@@ -3991,16 +3975,16 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word Thread_top_offset = 104;
 static constexpr dart::compiler::target::word Thread_top_resource_offset = 48;
 static constexpr dart::compiler::target::word
-    Thread_unboxed_int64_runtime_arg_offset = 200;
+    Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    Thread_write_barrier_entry_point_offset = 520;
+    Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
     80;
 static constexpr dart::compiler::target::word Thread_callback_code_offset =
-    1528;
+    1520;
 static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
     16;
 static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
@@ -4050,9 +4034,9 @@ static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384, 1392,
-        1400, 1408, 1416, 1424, -1,   -1,   -1,   -1,   1432, 1440, -1,
-        -1,   1448, 1456, 1464, -1,   -1,   -1,   -1,   -1,   -1};
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
 static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word Array_header_size = 24;
@@ -4375,148 +4359,146 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 376;
+    AOT_Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 696;
+    AOT_Thread_active_exception_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 700;
+    AOT_Thread_active_stacktrace_offset = 692;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 128;
+    AOT_Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 272;
+    AOT_Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 288;
+    AOT_Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 196;
+    AOT_Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 292;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 200;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 296;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 204;
+    AOT_Thread_allocate_object_slow_stub_offset = 196;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    732;
+    724;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 96;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 340;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 332;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    120;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 116;
+    112;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 276;
+    AOT_Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 144;
+    AOT_Thread_call_to_runtime_stub_offset = 136;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    740;
+    732;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    316;
+    308;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 320;
+    AOT_Thread_deoptimize_entry_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 236;
+    AOT_Thread_deoptimize_stub_offset = 228;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 356;
+    AOT_Thread_double_abs_address_offset = 348;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 352;
+    AOT_Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 256;
+    AOT_Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 716;
+    AOT_Thread_execution_state_offset = 708;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 260;
+    AOT_Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 264;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 324;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 136;
+    AOT_Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 132;
+    AOT_Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 368;
+    AOT_Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 364;
+    AOT_Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 360;
+    AOT_Thread_float_not_address_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 372;
+    AOT_Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 704;
+    AOT_Thread_global_object_pool_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 140;
+    AOT_Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 728;
+    AOT_Thread_exit_through_ffi_offset = 720;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 68;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 240;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 244;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 252;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 308;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 312;
+    AOT_Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 216;
+    AOT_Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        148;
+        140;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    112;
+    104;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset = 708;
+    AOT_Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset = 700;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 712;
+    AOT_Thread_saved_shadow_call_stack_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 720;
+    AOT_Thread_safepoint_state_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 248;
+    AOT_Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 328;
+    AOT_Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     36;
 static constexpr dart::compiler::target::word
@@ -4524,13 +4506,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 80;
 static constexpr dart::compiler::target::word
@@ -4539,16 +4521,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 52;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     24;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 104;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 124;
+    AOT_Thread_write_barrier_code_offset = 116;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 268;
+    AOT_Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 40;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    724;
+    716;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -4613,7 +4595,7 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     4, 12, 8, 16};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        664, 668, 672, 676, 680, -1, 684, -1, 688, 692, -1, -1, -1, -1, -1, -1};
+        656, 660, 664, 668, 672, -1, 676, -1, 680, 684, -1, -1, -1, -1, -1, -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 8;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 12;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 12;
@@ -4949,149 +4931,147 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 736;
+    AOT_Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 1400;
+    AOT_Thread_active_exception_offset = 1392;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 1408;
+    AOT_Thread_active_stacktrace_offset = 1400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 240;
+    AOT_Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 528;
+    AOT_Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 560;
+    AOT_Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 376;
+    AOT_Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 568;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 384;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 576;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 392;
+    AOT_Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    1472;
+    1464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 192;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 664;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 656;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    224;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 216;
+    216;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 536;
+    AOT_Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 272;
+    AOT_Thread_call_to_runtime_stub_offset = 264;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    1488;
+    1480;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    616;
+    608;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    448;
+    440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 624;
+    AOT_Thread_deoptimize_entry_offset = 616;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 456;
+    AOT_Thread_deoptimize_stub_offset = 448;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 696;
+    AOT_Thread_double_abs_address_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 688;
+    AOT_Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 496;
+    AOT_Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 1440;
+    AOT_Thread_execution_state_offset = 1432;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 504;
+    AOT_Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 512;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 632;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 256;
+    AOT_Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 248;
+    AOT_Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 720;
+    AOT_Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 712;
+    AOT_Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 704;
+    AOT_Thread_float_not_address_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 728;
+    AOT_Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 1416;
+    AOT_Thread_global_object_pool_offset = 1408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 264;
+    AOT_Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 1464;
+    AOT_Thread_exit_through_ffi_offset = 1456;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 136;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 464;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 472;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 488;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 600;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 608;
+    AOT_Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 416;
+    AOT_Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        280;
+        272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    208;
+    200;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 672;
+    AOT_Thread_predefined_symbols_address_offset = 664;
 static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
-    1424;
+    1416;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 1432;
+    AOT_Thread_saved_shadow_call_stack_offset = 1424;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 1448;
+    AOT_Thread_safepoint_state_offset = 1440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 480;
+    AOT_Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 640;
+    AOT_Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     72;
 static constexpr dart::compiler::target::word
@@ -5099,13 +5079,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 160;
 static constexpr dart::compiler::target::word
@@ -5114,16 +5094,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 104;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     48;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 200;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 232;
+    AOT_Thread_write_barrier_code_offset = 224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 520;
+    AOT_Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 80;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    1456;
+    1448;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 16;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -5188,8 +5168,8 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, -1,   -1,   1344, 1352,
-        1360, 1368, 1376, -1,   1384, 1392, -1,   -1};
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
@@ -5528,149 +5508,147 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 736;
+    AOT_Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 1472;
+    AOT_Thread_active_exception_offset = 1464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 1480;
+    AOT_Thread_active_stacktrace_offset = 1472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 240;
+    AOT_Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 528;
+    AOT_Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 560;
+    AOT_Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 376;
+    AOT_Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 568;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 384;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 576;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 392;
+    AOT_Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    1544;
+    1536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 192;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 664;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 656;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    224;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 216;
+    216;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 536;
+    AOT_Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 272;
+    AOT_Thread_call_to_runtime_stub_offset = 264;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    1560;
+    1552;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    616;
+    608;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    448;
+    440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 624;
+    AOT_Thread_deoptimize_entry_offset = 616;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 456;
+    AOT_Thread_deoptimize_stub_offset = 448;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 696;
+    AOT_Thread_double_abs_address_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 688;
+    AOT_Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 496;
+    AOT_Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 1512;
+    AOT_Thread_execution_state_offset = 1504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 504;
+    AOT_Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 512;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 632;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 256;
+    AOT_Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 248;
+    AOT_Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 720;
+    AOT_Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 712;
+    AOT_Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 704;
+    AOT_Thread_float_not_address_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 728;
+    AOT_Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 1488;
+    AOT_Thread_global_object_pool_offset = 1480;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 264;
+    AOT_Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 1536;
+    AOT_Thread_exit_through_ffi_offset = 1528;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 136;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 464;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 472;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 488;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 600;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 608;
+    AOT_Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 416;
+    AOT_Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        280;
+        272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    208;
+    200;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 672;
+    AOT_Thread_predefined_symbols_address_offset = 664;
 static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
-    1496;
+    1488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 1504;
+    AOT_Thread_saved_shadow_call_stack_offset = 1496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 1520;
+    AOT_Thread_safepoint_state_offset = 1512;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 480;
+    AOT_Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 640;
+    AOT_Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     72;
 static constexpr dart::compiler::target::word
@@ -5678,13 +5656,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 160;
 static constexpr dart::compiler::target::word
@@ -5693,16 +5671,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 104;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     48;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 200;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 232;
+    AOT_Thread_write_barrier_code_offset = 224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 520;
+    AOT_Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 80;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    1528;
+    1520;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 16;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -5767,9 +5745,9 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384, 1392,
-        1400, 1408, 1416, 1424, -1,   -1,   -1,   -1,   1432, 1440, -1,
-        -1,   1448, 1456, 1464, -1,   -1,   -1,   -1,   -1,   -1};
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
@@ -6102,148 +6080,146 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 4;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 4;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 376;
+    AOT_Thread_AllocateArray_entry_point_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 696;
+    AOT_Thread_active_exception_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 700;
+    AOT_Thread_active_stacktrace_offset = 692;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 128;
+    AOT_Thread_array_write_barrier_code_offset = 120;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 272;
+    AOT_Thread_array_write_barrier_entry_point_offset = 264;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 280;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 188;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 180;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 284;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 276;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 192;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 288;
+    AOT_Thread_allocate_object_entry_point_offset = 280;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 196;
+    AOT_Thread_allocate_object_stub_offset = 188;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 292;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 284;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 200;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 192;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 296;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 204;
+    AOT_Thread_allocate_object_slow_stub_offset = 196;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    732;
+    724;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 96;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 340;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 332;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    120;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 116;
+    112;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 108;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 332;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 324;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 276;
+    AOT_Thread_call_to_runtime_entry_point_offset = 268;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 144;
+    AOT_Thread_call_to_runtime_stub_offset = 136;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    740;
+    732;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 48;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    316;
+    308;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    232;
+    224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 320;
+    AOT_Thread_deoptimize_entry_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 236;
+    AOT_Thread_deoptimize_stub_offset = 228;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 356;
+    AOT_Thread_double_abs_address_offset = 348;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 352;
+    AOT_Thread_double_negate_address_offset = 344;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 56;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 256;
+    AOT_Thread_enter_safepoint_stub_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 716;
+    AOT_Thread_execution_state_offset = 708;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 260;
+    AOT_Thread_exit_safepoint_stub_offset = 252;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 264;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 324;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 316;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 136;
+    AOT_Thread_fix_allocation_stub_code_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 132;
+    AOT_Thread_fix_callers_target_code_offset = 124;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 368;
+    AOT_Thread_float_absolute_address_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 364;
+    AOT_Thread_float_negate_address_offset = 356;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 360;
+    AOT_Thread_float_not_address_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 372;
+    AOT_Thread_float_zerow_address_offset = 364;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 704;
+    AOT_Thread_global_object_pool_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 140;
+    AOT_Thread_invoke_dart_code_stub_offset = 132;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 728;
+    AOT_Thread_exit_through_ffi_offset = 720;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 44;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 68;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 240;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 244;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 236;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 252;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 244;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 84;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 308;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 300;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 312;
+    AOT_Thread_switchable_call_miss_entry_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 216;
+    AOT_Thread_switchable_call_miss_stub_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 336;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 152;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 144;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        148;
+        140;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 160;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 152;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 156;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 148;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 168;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 160;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 164;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 156;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 176;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 172;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 164;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 184;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 176;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 180;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 172;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    112;
+    104;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 344;
-static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset = 708;
+    AOT_Thread_predefined_symbols_address_offset = 336;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset = 700;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 712;
+    AOT_Thread_saved_shadow_call_stack_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 720;
+    AOT_Thread_safepoint_state_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 248;
+    AOT_Thread_slow_type_test_stub_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 328;
+    AOT_Thread_slow_type_test_entry_point_offset = 320;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     36;
 static constexpr dart::compiler::target::word
@@ -6251,13 +6227,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 64;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 304;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 212;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 204;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 300;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 292;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 208;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 200;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 80;
 static constexpr dart::compiler::target::word
@@ -6266,16 +6242,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 52;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     24;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 104;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 92;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 124;
+    AOT_Thread_write_barrier_code_offset = 116;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 268;
+    AOT_Thread_write_barrier_entry_point_offset = 260;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 40;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    724;
+    716;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 8;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -6337,7 +6313,7 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     4, 12, 8, 16};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        664, 668, 672, 676, 680, -1, 684, -1, 688, 692, -1, -1, -1, -1, -1, -1};
+        656, 660, 664, 668, 672, -1, 676, -1, 680, 684, -1, -1, -1, -1, -1, -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 8;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 12;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 12;
@@ -6669,149 +6645,147 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 736;
+    AOT_Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 1400;
+    AOT_Thread_active_exception_offset = 1392;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 1408;
+    AOT_Thread_active_stacktrace_offset = 1400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 240;
+    AOT_Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 528;
+    AOT_Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 560;
+    AOT_Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 376;
+    AOT_Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 568;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 384;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 576;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 392;
+    AOT_Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    1472;
+    1464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 192;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 664;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 656;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    224;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 216;
+    216;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 536;
+    AOT_Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 272;
+    AOT_Thread_call_to_runtime_stub_offset = 264;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    1488;
+    1480;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    616;
+    608;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    448;
+    440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 624;
+    AOT_Thread_deoptimize_entry_offset = 616;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 456;
+    AOT_Thread_deoptimize_stub_offset = 448;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 696;
+    AOT_Thread_double_abs_address_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 688;
+    AOT_Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 496;
+    AOT_Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 1440;
+    AOT_Thread_execution_state_offset = 1432;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 504;
+    AOT_Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 512;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 632;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 256;
+    AOT_Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 248;
+    AOT_Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 720;
+    AOT_Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 712;
+    AOT_Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 704;
+    AOT_Thread_float_not_address_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 728;
+    AOT_Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 1416;
+    AOT_Thread_global_object_pool_offset = 1408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 264;
+    AOT_Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 1464;
+    AOT_Thread_exit_through_ffi_offset = 1456;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 136;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 464;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 472;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 488;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 600;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 608;
+    AOT_Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 416;
+    AOT_Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        280;
+        272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    208;
+    200;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 672;
+    AOT_Thread_predefined_symbols_address_offset = 664;
 static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
-    1424;
+    1416;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 1432;
+    AOT_Thread_saved_shadow_call_stack_offset = 1424;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 1448;
+    AOT_Thread_safepoint_state_offset = 1440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 480;
+    AOT_Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 640;
+    AOT_Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     72;
 static constexpr dart::compiler::target::word
@@ -6819,13 +6793,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 160;
 static constexpr dart::compiler::target::word
@@ -6834,16 +6808,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 104;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     48;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 200;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 232;
+    AOT_Thread_write_barrier_code_offset = 224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 520;
+    AOT_Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 80;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    1456;
+    1448;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 16;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -6905,8 +6879,8 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, -1,   -1,   1344, 1352,
-        1360, 1368, 1376, -1,   1384, 1392, -1,   -1};
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
@@ -7241,149 +7215,147 @@ static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
 static constexpr dart::compiler::target::word
     AOT_SubtypeTestCache_cache_offset = 8;
 static constexpr dart::compiler::target::word
-    AOT_Thread_AllocateArray_entry_point_offset = 736;
+    AOT_Thread_AllocateArray_entry_point_offset = 728;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_exception_offset = 1472;
+    AOT_Thread_active_exception_offset = 1464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_active_stacktrace_offset = 1480;
+    AOT_Thread_active_stacktrace_offset = 1472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_code_offset = 240;
+    AOT_Thread_array_write_barrier_code_offset = 232;
 static constexpr dart::compiler::target::word
-    AOT_Thread_array_write_barrier_entry_point_offset = 528;
+    AOT_Thread_array_write_barrier_entry_point_offset = 520;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 544;
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 360;
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 352;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 552;
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 544;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 368;
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 360;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_entry_point_offset = 560;
+    AOT_Thread_allocate_object_entry_point_offset = 552;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_stub_offset = 376;
+    AOT_Thread_allocate_object_stub_offset = 368;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_entry_point_offset = 568;
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 560;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_parameterized_stub_offset = 384;
+    AOT_Thread_allocate_object_parameterized_stub_offset = 376;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_entry_point_offset = 576;
+    AOT_Thread_allocate_object_slow_entry_point_offset = 568;
 static constexpr dart::compiler::target::word
-    AOT_Thread_allocate_object_slow_stub_offset = 392;
+    AOT_Thread_allocate_object_slow_stub_offset = 384;
 static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
-    1544;
+    1536;
 static constexpr dart::compiler::target::word
-    AOT_Thread_async_stack_trace_offset = 192;
-static constexpr dart::compiler::target::word
-    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 664;
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 656;
 static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
-    224;
-static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 216;
+    216;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 208;
 static constexpr dart::compiler::target::word
-    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 648;
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 640;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_entry_point_offset = 536;
+    AOT_Thread_call_to_runtime_entry_point_offset = 528;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_to_runtime_stub_offset = 272;
+    AOT_Thread_call_to_runtime_stub_offset = 264;
 static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
-    1560;
+    1552;
 static constexpr dart::compiler::target::word
     AOT_Thread_dispatch_table_array_offset = 96;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
-    616;
+    608;
 static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
-    448;
+    440;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_entry_offset = 624;
+    AOT_Thread_deoptimize_entry_offset = 616;
 static constexpr dart::compiler::target::word
-    AOT_Thread_deoptimize_stub_offset = 456;
+    AOT_Thread_deoptimize_stub_offset = 448;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_abs_address_offset = 696;
+    AOT_Thread_double_abs_address_offset = 688;
 static constexpr dart::compiler::target::word
-    AOT_Thread_double_negate_address_offset = 688;
+    AOT_Thread_double_negate_address_offset = 680;
 static constexpr dart::compiler::target::word AOT_Thread_end_offset = 112;
 static constexpr dart::compiler::target::word
-    AOT_Thread_enter_safepoint_stub_offset = 496;
+    AOT_Thread_enter_safepoint_stub_offset = 488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_execution_state_offset = 1512;
+    AOT_Thread_execution_state_offset = 1504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_safepoint_stub_offset = 504;
+    AOT_Thread_exit_safepoint_stub_offset = 496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_stub_offset = 512;
+    AOT_Thread_call_native_through_safepoint_stub_offset = 504;
 static constexpr dart::compiler::target::word
-    AOT_Thread_call_native_through_safepoint_entry_point_offset = 632;
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 624;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_allocation_stub_code_offset = 256;
+    AOT_Thread_fix_allocation_stub_code_offset = 248;
 static constexpr dart::compiler::target::word
-    AOT_Thread_fix_callers_target_code_offset = 248;
+    AOT_Thread_fix_callers_target_code_offset = 240;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_absolute_address_offset = 720;
+    AOT_Thread_float_absolute_address_offset = 712;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_negate_address_offset = 712;
+    AOT_Thread_float_negate_address_offset = 704;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_not_address_offset = 704;
+    AOT_Thread_float_not_address_offset = 696;
 static constexpr dart::compiler::target::word
-    AOT_Thread_float_zerow_address_offset = 728;
+    AOT_Thread_float_zerow_address_offset = 720;
 static constexpr dart::compiler::target::word
-    AOT_Thread_global_object_pool_offset = 1488;
+    AOT_Thread_global_object_pool_offset = 1480;
 static constexpr dart::compiler::target::word
-    AOT_Thread_invoke_dart_code_stub_offset = 264;
+    AOT_Thread_invoke_dart_code_stub_offset = 256;
 static constexpr dart::compiler::target::word
-    AOT_Thread_exit_through_ffi_offset = 1536;
+    AOT_Thread_exit_through_ffi_offset = 1528;
 static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 88;
 static constexpr dart::compiler::target::word
     AOT_Thread_field_table_values_offset = 136;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_return_stub_offset = 464;
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 456;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_deopt_from_throw_stub_offset = 472;
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 464;
 static constexpr dart::compiler::target::word
-    AOT_Thread_lazy_specialize_type_test_stub_offset = 488;
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 480;
 static constexpr dart::compiler::target::word
     AOT_Thread_marking_stack_block_offset = 168;
 static constexpr dart::compiler::target::word
-    AOT_Thread_megamorphic_call_checked_entry_offset = 600;
+    AOT_Thread_megamorphic_call_checked_entry_offset = 592;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_entry_offset = 608;
+    AOT_Thread_switchable_call_miss_entry_offset = 600;
 static constexpr dart::compiler::target::word
-    AOT_Thread_switchable_call_miss_stub_offset = 416;
+    AOT_Thread_switchable_call_miss_stub_offset = 408;
 static constexpr dart::compiler::target::word
-    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 656;
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 648;
 static constexpr dart::compiler::target::word
-    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 288;
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 280;
 static constexpr dart::compiler::target::word
     AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
-        280;
+        272;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 304;
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 296;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 296;
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 288;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 320;
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 312;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 312;
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 304;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 336;
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 328;
 static constexpr dart::compiler::target::word
-    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 328;
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 320;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 352;
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 344;
 static constexpr dart::compiler::target::word
-    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 344;
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 336;
 static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
-    208;
+    200;
 static constexpr dart::compiler::target::word
-    AOT_Thread_predefined_symbols_address_offset = 672;
+    AOT_Thread_predefined_symbols_address_offset = 664;
 static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
-    1496;
+    1488;
 static constexpr dart::compiler::target::word
-    AOT_Thread_saved_shadow_call_stack_offset = 1504;
+    AOT_Thread_saved_shadow_call_stack_offset = 1496;
 static constexpr dart::compiler::target::word
-    AOT_Thread_safepoint_state_offset = 1520;
+    AOT_Thread_safepoint_state_offset = 1512;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_stub_offset = 480;
+    AOT_Thread_slow_type_test_stub_offset = 472;
 static constexpr dart::compiler::target::word
-    AOT_Thread_slow_type_test_entry_point_offset = 640;
+    AOT_Thread_slow_type_test_entry_point_offset = 632;
 static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
     72;
 static constexpr dart::compiler::target::word
@@ -7391,13 +7363,13 @@ static constexpr dart::compiler::target::word
 static constexpr dart::compiler::target::word
     AOT_Thread_stack_overflow_flags_offset = 128;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 592;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 584;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 408;
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 400;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 584;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 576;
 static constexpr dart::compiler::target::word
-    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 400;
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 392;
 static constexpr dart::compiler::target::word
     AOT_Thread_store_buffer_block_offset = 160;
 static constexpr dart::compiler::target::word
@@ -7406,16 +7378,16 @@ static constexpr dart::compiler::target::word AOT_Thread_top_offset = 104;
 static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
     48;
 static constexpr dart::compiler::target::word
-    AOT_Thread_unboxed_int64_runtime_arg_offset = 200;
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 192;
 static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 184;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_code_offset = 232;
+    AOT_Thread_write_barrier_code_offset = 224;
 static constexpr dart::compiler::target::word
-    AOT_Thread_write_barrier_entry_point_offset = 520;
+    AOT_Thread_write_barrier_entry_point_offset = 512;
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_mask_offset = 80;
 static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
-    1528;
+    1520;
 static constexpr dart::compiler::target::word
     AOT_TimelineStream_enabled_offset = 16;
 static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
@@ -7477,9 +7449,9 @@ static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
     8, 24, 16, 32};
 static constexpr dart::compiler::target::word
     AOT_Thread_write_barrier_wrappers_thread_offset[] = {
-        1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384, 1392,
-        1400, 1408, 1416, 1424, -1,   -1,   -1,   -1,   1432, 1440, -1,
-        -1,   1448, 1456, 1464, -1,   -1,   -1,   -1,   -1,   -1};
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
 static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
 static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
 static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
diff --git a/runtime/vm/compiler/runtime_offsets_list.h b/runtime/vm/compiler/runtime_offsets_list.h
index 8b5aa0ae6c5..fc6cfdcf420 100644
--- a/runtime/vm/compiler/runtime_offsets_list.h
+++ b/runtime/vm/compiler/runtime_offsets_list.h
@@ -181,7 +181,6 @@
   FIELD(Thread, allocate_object_slow_entry_point_offset)                       \
   FIELD(Thread, allocate_object_slow_stub_offset)                              \
   FIELD(Thread, api_top_scope_offset)                                          \
-  FIELD(Thread, async_stack_trace_offset)                                      \
   FIELD(Thread, auto_scope_native_wrapper_entry_point_offset)                  \
   FIELD(Thread, bool_false_offset)                                             \
   FIELD(Thread, bool_true_offset)                                              \
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index b42149ec194..9dd66545322 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -215,6 +215,10 @@ char* Dart::Init(const uint8_t* vm_isolate_snapshot,
     return Utils::StrDup(
         "To use --lazy-async-stacks, please disable --causal-async-stacks!");
   }
+  // TODO(cskau): Remove once flag deprecation has been completed.
+  if (FLAG_causal_async_stacks) {
+    return Utils::StrDup("--causal-async-stacks is deprecated!");
+  }
 
   FrameLayout::Init();
 
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index c64c7a1a82d..05681c1e4e0 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -5501,11 +5501,6 @@ StringPtr Api::GetEnvironmentValue(Thread* thread, const String& name) {
     if (Symbols::DartIsVM().Equals(name)) {
       return Symbols::True().raw();
     }
-    if (FLAG_causal_async_stacks) {
-      if (Symbols::DartDeveloperCausalAsyncStacks().Equals(name)) {
-        return Symbols::True().raw();
-      }
-    }
   }
   return result.raw();
 }
diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index ceb0e2e6ab8..5f3ca298563 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -731,10 +731,6 @@ ObjectPtr ActivationFrame::GetAsyncAwaiter(
   return Object::null();
 }
 
-ObjectPtr ActivationFrame::GetCausalStack() {
-  return GetAsyncContextVariable(Symbols::AsyncStackTraceVar());
-}
-
 bool ActivationFrame::HandlesException(const Instance& exc_obj) {
   if ((kind_ == kAsyncSuspensionMarker) || (kind_ == kAsyncCausal)) {
     // These frames are historical.
@@ -1823,97 +1819,9 @@ DebuggerStackTrace* Debugger::CollectAsyncCausalStackTrace() {
     return CollectAsyncLazyStackTrace();
   }
   if (!FLAG_causal_async_stacks) {
-    return NULL;
+    return nullptr;
   }
-  Thread* thread = Thread::Current();
-  Zone* zone = thread->zone();
-  Isolate* isolate = thread->isolate();
-  DebuggerStackTrace* stack_trace = new DebuggerStackTrace(8);
-
-  Object& code_obj = Object::Handle(zone);
-  Code& code = Code::Handle(zone);
-  Smi& offset = Smi::Handle();
-  Code& inlined_code = Code::Handle(zone);
-  Array& deopt_frame = Array::Handle(zone);
-
-  Function& async_function = Function::Handle(zone);
-  class StackTrace& async_stack_trace = StackTrace::Handle(zone);
-  Array& async_code_array = Array::Handle(zone);
-  Array& async_pc_offset_array = Array::Handle(zone);
-
-  // Extract the eagerly recorded async stack from the current thread.
-  StackTraceUtils::ExtractAsyncStackTraceInfo(
-      thread, &async_function, &async_stack_trace, &async_code_array,
-      &async_pc_offset_array);
-
-  if (async_function.IsNull()) {
-    return NULL;
-  }
-
-  bool sync_async_end = false;
-  intptr_t synchronous_stack_trace_length =
-      StackTraceUtils::CountFrames(thread, 0, async_function, &sync_async_end);
-
-  // Append the top frames from the synchronous stack trace, up until the active
-  // asynchronous function. We truncate the remainder of the synchronous
-  // stack trace because it contains activations that are part of the
-  // asynchronous dispatch mechanisms.
-  StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
-                              Thread::Current(),
-                              StackFrameIterator::kNoCrossThreadIteration);
-  StackFrame* frame = iterator.NextFrame();
-  while (synchronous_stack_trace_length > 0) {
-    ASSERT(frame != NULL);
-    if (frame->IsDartFrame()) {
-      code = frame->LookupDartCode();
-      AppendCodeFrames(thread, isolate, zone, stack_trace, frame, &code,
-                       &inlined_code, &deopt_frame);
-      synchronous_stack_trace_length--;
-    }
-    frame = iterator.NextFrame();
-  }
-
-  // Now we append the asynchronous causal stack trace. These are not active
-  // frames but a historical record of how this asynchronous function was
-  // activated.
-
-  intptr_t frame_skip =
-      sync_async_end ? StackTrace::kSyncAsyncCroppedFrames : 0;
-  while (!async_stack_trace.IsNull()) {
-    for (intptr_t i = frame_skip; i < async_stack_trace.Length(); i++) {
-      code_obj = async_stack_trace.CodeAtFrame(i);
-      if (code_obj.IsNull()) {
-        break;
-      }
-      if (code_obj.raw() == StubCode::AsynchronousGapMarker().raw()) {
-        stack_trace->AddMarker(ActivationFrame::kAsyncSuspensionMarker);
-        // The frame immediately below the asynchronous gap marker is the
-        // identical to the frame above the marker. Skip the frame to enhance
-        // the readability of the trace.
-        i++;
-      } else {
-        offset = Smi::RawCast(async_stack_trace.PcOffsetAtFrame(i));
-        code ^= code_obj.raw();
-        uword pc = code.PayloadStart() + offset.Value();
-        if (code.is_optimized()) {
-          for (InlinedFunctionsIterator it(code, pc); !it.Done();
-               it.Advance()) {
-            inlined_code = it.code();
-            stack_trace->AddAsyncCausalFrame(it.pc(), inlined_code);
-          }
-        } else {
-          stack_trace->AddAsyncCausalFrame(pc, code);
-        }
-      }
-    }
-    // Follow the link.
-    frame_skip = async_stack_trace.skip_sync_start_in_parent_stack()
-                     ? StackTrace::kSyncAsyncCroppedFrames
-                     : 0;
-    async_stack_trace = async_stack_trace.async_link();
-  }
-
-  return stack_trace;
+  UNREACHABLE();  //  FLAG_causal_async_stacks is deprecated.
 }
 
 DebuggerStackTrace* Debugger::CollectAsyncLazyStackTrace() {
@@ -2005,16 +1913,12 @@ DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
                               Thread::Current(),
                               StackFrameIterator::kNoCrossThreadIteration);
 
-  Object& code_object = Object::Handle(zone);
   Code& code = Code::Handle(zone);
-  Smi& offset = Smi::Handle(zone);
   Function& function = Function::Handle(zone);
   Code& inlined_code = Code::Handle(zone);
   Closure& async_activation = Closure::Handle(zone);
   Object& next_async_activation = Object::Handle(zone);
   Array& deopt_frame = Array::Handle(zone);
-  // Note: 'class' since Debugger declares a method by the same name.
-  class StackTrace& async_stack_trace = StackTrace::Handle(zone);
   bool stack_has_async_function = false;
   Closure& closure = Closure::Handle();
 
@@ -2046,7 +1950,6 @@ DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
         stack_has_async_function = true;
         // Grab the awaiter.
         async_activation ^= activation->GetAsyncAwaiter(&caller_closure_finder);
-        async_stack_trace ^= activation->GetCausalStack();
         // Bail if we've reach the end of sync execution stack.
         ObjectPtr* last_caller_obj =
             reinterpret_cast<ObjectPtr*>(frame->GetCallerSp());
@@ -2102,7 +2005,6 @@ DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
         stack_has_async_function = true;
         // Grab the awaiter.
         async_activation ^= activation->GetAsyncAwaiter(&caller_closure_finder);
-        async_stack_trace ^= activation->GetCausalStack();
         found_async_awaiter = true;
       } else {
         stack_trace->AddActivation(CollectDartFrame(isolate, it.pc(), frame,
@@ -2129,8 +2031,6 @@ DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
 
     if (!(activation->function().IsAsyncClosure() ||
           activation->function().IsAsyncGenClosure())) {
-      // No more awaiters. Extract the causal stack trace (if it exists).
-      async_stack_trace ^= activation->GetCausalStack();
       break;
     }
 
@@ -2145,59 +2045,12 @@ DebuggerStackTrace* Debugger::CollectAwaiterReturnStackTrace() {
 
     next_async_activation = activation->GetAsyncAwaiter(&caller_closure_finder);
     if (next_async_activation.IsNull()) {
-      // No more awaiters. Extract the causal stack trace (if it exists).
-      async_stack_trace ^= activation->GetCausalStack();
       break;
     }
 
     async_activation = Closure::RawCast(next_async_activation.raw());
   }
 
-  // Now we append the asynchronous causal stack trace. These are not active
-  // frames but a historical record of how this asynchronous function was
-  // activated.
-  while (!async_stack_trace.IsNull()) {
-    for (intptr_t i = 0; i < async_stack_trace.Length(); i++) {
-      code_object = async_stack_trace.CodeAtFrame(i);
-
-      if (code_object.raw() == Code::null()) {
-        // Incomplete OutOfMemory/StackOverflow trace OR array padding.
-        break;
-      }
-
-      if (code_object.raw() == StubCode::AsynchronousGapMarker().raw()) {
-        stack_trace->AddMarker(ActivationFrame::kAsyncSuspensionMarker);
-        // The frame immediately below the asynchronous gap marker is the
-        // identical to the frame above the marker. Skip the frame to enhance
-        // the readability of the trace.
-        i++;
-        continue;
-      }
-
-      code_object = async_stack_trace.CodeAtFrame(i);
-      offset = Smi::RawCast(async_stack_trace.PcOffsetAtFrame(i));
-      code ^= code_object.raw();
-      if (FLAG_trace_debugger_stacktrace) {
-        OS::PrintErr(
-            "CollectAwaiterReturnStackTrace: visiting frame %" Pd
-            " in async causal stack trace:\n\t%s\n",
-            i, Function::Handle(code.function()).ToFullyQualifiedCString());
-      }
-      uword pc = code.PayloadStart() + offset.Value();
-      if (code.is_optimized()) {
-        for (InlinedFunctionsIterator it(code, pc); !it.Done(); it.Advance()) {
-          inlined_code = it.code();
-          stack_trace->AddAsyncCausalFrame(it.pc(), inlined_code);
-        }
-      } else {
-        stack_trace->AddAsyncCausalFrame(pc, code);
-      }
-    }
-
-    // Follow the link.
-    async_stack_trace = async_stack_trace.async_link();
-  }
-
   return stack_trace;
 #endif  // defined(DART_PRECOMPILED_RUNTIME)
 }
@@ -3744,9 +3597,7 @@ ErrorPtr Debugger::PauseStepping() {
     }
   }
 
-  // Since lazy async stacks doesn't use the _asyncStackTraceHelper runtime
-  // entry, we need to manually set a synthetic breakpoint for async_op before
-  // we enter it.
+  // We need to manually set a synthetic breakpoint for async_op before entry.
   if (FLAG_lazy_async_stacks) {
     // async and async* functions always contain synthetic async_ops.
     if ((frame->function().IsAsyncFunction() ||
diff --git a/runtime/vm/debugger.h b/runtime/vm/debugger.h
index 18691a4414a..0312163ce86 100644
--- a/runtime/vm/debugger.h
+++ b/runtime/vm/debugger.h
@@ -338,8 +338,6 @@ class ActivationFrame : public ZoneAllocated {
   // Get Closure that await'ed this async frame.
   ObjectPtr GetAsyncAwaiter(CallerClosureFinder* caller_closure_finder);
 
-  ObjectPtr GetCausalStack();
-
   bool HandlesException(const Instance& exc_obj);
 
  private:
diff --git a/runtime/vm/flag_list.h b/runtime/vm/flag_list.h
index dd6c196ff64..36303f8915d 100644
--- a/runtime/vm/flag_list.h
+++ b/runtime/vm/flag_list.h
@@ -52,10 +52,11 @@ constexpr bool kDartUseBackgroundCompilation = true;
 //
 // The syntax used is the same as that for FLAG_LIST below, as these flags are
 // automatically included in FLAG_LIST.
+// TODO(cskau): Remove causal_async_stacks when deprecated.
 #define VM_GLOBAL_FLAG_LIST(P, R, C, D)                                        \
   P(dwarf_stack_traces_mode, bool, false,                                      \
     "Use --[no-]dwarf-stack-traces instead.")                                  \
-  P(causal_async_stacks, bool, false, "Improved async stacks")                 \
+  P(causal_async_stacks, bool, false, "DEPRECATED: Improved async stacks")     \
   P(lazy_async_stacks, bool, true, "Reconstruct async stacks from listeners")  \
   P(lazy_dispatchers, bool, true, "Generate dispatchers lazily")               \
   P(use_bare_instructions, bool, true, "Enable bare instructions mode.")       \
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 565e5b91575..a70957735a1 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -13897,7 +13897,6 @@ void Library::CheckFunctionFingerprints() {
   all_libs.Add(&Library::ZoneHandle(Library::ConvertLibrary()));
   all_libs.Add(&Library::ZoneHandle(Library::InternalLibrary()));
   all_libs.Add(&Library::ZoneHandle(Library::FfiLibrary()));
-  ASYNC_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS_ASM_INTRINSIC);
   INTERNAL_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS_ASM_INTRINSIC);
   OTHER_RECOGNIZED_LIST(CHECK_FINGERPRINTS_OTHER);
   POLYMORPHIC_TARGET_LIST(CHECK_FINGERPRINTS);
diff --git a/runtime/vm/object_store.cc b/runtime/vm/object_store.cc
index 5031b697b14..143a7bb77e7 100644
--- a/runtime/vm/object_store.cc
+++ b/runtime/vm/object_store.cc
@@ -218,19 +218,6 @@ void ObjectStore::InitKnownObjects() {
 
   String& function_name = String::Handle(zone);
   Function& function = Function::Handle(zone);
-  function_name = async_lib.PrivateName(Symbols::SetAsyncThreadStackTrace());
-  ASSERT(!function_name.IsNull());
-  function = Resolver::ResolveStatic(async_lib, Object::null_string(),
-                                     function_name, 0, 1, Object::null_array());
-  ASSERT(!function.IsNull());
-  set_async_set_thread_stack_trace(function);
-
-  function_name = async_lib.PrivateName(Symbols::ClearAsyncThreadStackTrace());
-  ASSERT(!function_name.IsNull());
-  function = Resolver::ResolveStatic(async_lib, Object::null_string(),
-                                     function_name, 0, 0, Object::null_array());
-  ASSERT(!function.IsNull());
-  set_async_clear_thread_stack_trace(function);
 
   function_name = async_lib.PrivateName(Symbols::AsyncStarMoveNextHelper());
   ASSERT(!function_name.IsNull());
diff --git a/runtime/vm/object_store.h b/runtime/vm/object_store.h
index d4b3d4a6feb..7ffcb713319 100644
--- a/runtime/vm/object_store.h
+++ b/runtime/vm/object_store.h
@@ -164,8 +164,6 @@ class ObjectPointerVisitor;
   RW(Function, simple_instance_of_function)                                    \
   RW(Function, simple_instance_of_true_function)                               \
   RW(Function, simple_instance_of_false_function)                              \
-  RW(Function, async_clear_thread_stack_trace)                                 \
-  RW(Function, async_set_thread_stack_trace)                                   \
   RW(Function, async_star_move_next_helper)                                    \
   RW(Function, complete_on_async_return)                                       \
   RW(Function, complete_on_async_error)                                        \
diff --git a/runtime/vm/scopes.cc b/runtime/vm/scopes.cc
index bed2d5c8e73..c84dc2630b7 100644
--- a/runtime/vm/scopes.cc
+++ b/runtime/vm/scopes.cc
@@ -345,10 +345,6 @@ static bool IsFilteredIdentifier(const String& str) {
     // Keep :is_sync for asynchronous debugging.
     return false;
   }
-  if (str.raw() == Symbols::AsyncStackTraceVar().raw()) {
-    // Keep :async_stack_trace for asynchronous debugging.
-    return false;
-  }
   if (str.raw() == Symbols::FunctionTypeArgumentsVar().raw()) {
     // Keep :function_type_arguments for accessing type variables in debugging.
     return false;
@@ -697,7 +693,6 @@ void LocalScope::CaptureLocalVariables(LocalScope* top_scope) {
     for (intptr_t i = 0; i < scope->num_variables(); i++) {
       LocalVariable* variable = scope->VariableAt(i);
       if (variable->is_forced_stack() ||
-          (variable->name().raw() == Symbols::StackTraceVar().raw()) ||
           (variable->name().raw() == Symbols::ExceptionVar().raw()) ||
           (variable->name().raw() == Symbols::SavedTryContextVar().raw()) ||
           (variable->name().raw() == Symbols::ArgDescVar().raw()) ||
diff --git a/runtime/vm/stack_trace.cc b/runtime/vm/stack_trace.cc
index 502a4f99323..fb01137127a 100644
--- a/runtime/vm/stack_trace.cc
+++ b/runtime/vm/stack_trace.cc
@@ -497,37 +497,4 @@ intptr_t StackTraceUtils::CollectFrames(Thread* thread,
   return collected_frames_count;
 }
 
-intptr_t StackTraceUtils::ExtractAsyncStackTraceInfo(
-    Thread* thread,
-    Function* async_function,
-    StackTrace* async_stack_trace_out,
-    Array* async_code_array,
-    Array* async_pc_offset_array) {
-  if (thread->async_stack_trace() == StackTrace::null()) {
-    return 0;
-  }
-  *async_stack_trace_out = thread->async_stack_trace();
-  ASSERT(!async_stack_trace_out->IsNull());
-  const StackTrace& async_stack_trace =
-      StackTrace::Handle(thread->async_stack_trace());
-  const intptr_t async_stack_trace_length = async_stack_trace.Length();
-  // At least two entries (0: gap marker, 1: async function).
-  RELEASE_ASSERT(async_stack_trace_length >= 2);
-  // Validate the structure of this stack trace.
-  *async_code_array = async_stack_trace.code_array();
-  ASSERT(!async_code_array->IsNull());
-  *async_pc_offset_array = async_stack_trace.pc_offset_array();
-  ASSERT(!async_pc_offset_array->IsNull());
-  // We start with the asynchronous gap marker.
-  ASSERT(async_code_array->At(0) != Code::null());
-  ASSERT(async_code_array->At(0) == StubCode::AsynchronousGapMarker().raw());
-  const Object& code_object = Object::Handle(async_code_array->At(1));
-  ASSERT(code_object.IsCode());
-  *async_function = Code::Cast(code_object).function();
-  ASSERT(!async_function->IsNull());
-  ASSERT(async_function->IsAsyncFunction() ||
-         async_function->IsAsyncGenerator());
-  return async_stack_trace_length;
-}
-
 }  // namespace dart
diff --git a/runtime/vm/stack_trace.h b/runtime/vm/stack_trace.h
index 460074bfaa8..215da831798 100644
--- a/runtime/vm/stack_trace.h
+++ b/runtime/vm/stack_trace.h
@@ -113,17 +113,6 @@ class StackTraceUtils : public AllStatic {
                                 intptr_t array_offset,
                                 intptr_t count,
                                 int skip_frames);
-
-  /// If |thread| has no async_stack_trace, does nothing.
-  /// Populates |async_function| with the top function of the async stack
-  /// trace. Populates |async_stack_trace|, |async_code_array|, and
-  /// |async_pc_offset_array| with the thread's async_stack_trace.
-  /// Returns the length of the asynchronous stack trace.
-  static intptr_t ExtractAsyncStackTraceInfo(Thread* thread,
-                                             Function* async_function,
-                                             StackTrace* async_stack_trace,
-                                             Array* async_code_array,
-                                             Array* async_pc_offset_array);
 };
 
 }  // namespace dart
diff --git a/runtime/vm/symbols.h b/runtime/vm/symbols.h
index 6e408a0ccd0..4ea837aa577 100644
--- a/runtime/vm/symbols.h
+++ b/runtime/vm/symbols.h
@@ -30,7 +30,6 @@ class ObjectPointerVisitor;
   V(AssignIndexToken, "[]=")                                                   \
   V(AsyncFuture, ":async_future")                                              \
   V(AsyncOperation, ":async_op")                                               \
-  V(AsyncStackTraceVar, ":async_stack_trace")                                  \
   V(AsyncStarMoveNextHelper, "_asyncStarMoveNextHelper")                       \
   V(AwaitContextVar, ":await_ctx_var")                                         \
   V(AwaitJumpVar, ":await_jump_var")                                           \
@@ -46,7 +45,6 @@ class ObjectPointerVisitor;
   V(CheckLoaded, "_checkLoaded")                                               \
   V(Class, "Class")                                                            \
   V(ClassID, "ClassID")                                                        \
-  V(ClearAsyncThreadStackTrace, "_clearAsyncThreadStackTrace")                 \
   V(ClosureData, "ClosureData")                                                \
   V(ClosureParameter, ":closure")                                              \
   V(Code, "Code")                                                              \
@@ -71,7 +69,6 @@ class ObjectPointerVisitor;
   V(DartCollection, "dart:collection")                                         \
   V(DartCore, "dart:core")                                                     \
   V(DartDeveloper, "dart:developer")                                           \
-  V(DartDeveloperCausalAsyncStacks, "dart.developer.causal_async_stacks")      \
   V(DartDeveloperTimeline, "dart.developer.timeline")                          \
   V(DartExtensionScheme, "dart-ext:")                                          \
   V(DartFfi, "dart:ffi")                                                       \
@@ -247,7 +244,6 @@ class ObjectPointerVisitor;
   V(Script, "Script")                                                          \
   V(SecondArg, "y")                                                            \
   V(Set, "set")                                                                \
-  V(SetAsyncThreadStackTrace, "_setAsyncThreadStackTrace")                     \
   V(SetterPrefix, "set:")                                                      \
   V(SignatureData, "SignatureData")                                            \
   V(SingleTargetCache, "SingleTargetCache")                                    \
@@ -258,7 +254,6 @@ class ObjectPointerVisitor;
   V(SpaceWhereNewLine, " where\n")                                             \
   V(StackOverflowError, "StackOverflowError")                                  \
   V(StackTraceParameter, ":stack_trace")                                       \
-  V(StackTraceVar, ":stack_trace_var")                                         \
   V(Stream, "stream")                                                          \
   V(StreamController, "StreamController")                                      \
   V(StreamIterator, "StreamIterator")                                          \
diff --git a/runtime/vm/thread.cc b/runtime/vm/thread.cc
index 68448fc7482..4b9652c4f96 100644
--- a/runtime/vm/thread.cc
+++ b/runtime/vm/thread.cc
@@ -71,7 +71,6 @@ Thread::Thread(bool is_vm_isolate)
       store_buffer_block_(NULL),
       marking_stack_block_(NULL),
       vm_tag_(0),
-      async_stack_trace_(StackTrace::null()),
       unboxed_int64_runtime_arg_(0),
       active_exception_(Object::null()),
       active_stacktrace_(Object::null()),
@@ -285,19 +284,6 @@ const char* Thread::TaskKindToCString(TaskKind kind) {
   }
 }
 
-StackTracePtr Thread::async_stack_trace() const {
-  return async_stack_trace_;
-}
-
-void Thread::set_async_stack_trace(const StackTrace& stack_trace) {
-  ASSERT(!stack_trace.IsNull());
-  async_stack_trace_ = stack_trace.raw();
-}
-
-void Thread::clear_async_stack_trace() {
-  async_stack_trace_ = StackTrace::null();
-}
-
 bool Thread::EnterIsolate(Isolate* isolate) {
   const bool kIsMutatorThread = true;
   Thread* thread = isolate->ScheduleThread(kIsMutatorThread);
@@ -667,7 +653,6 @@ void Thread::VisitObjectPointers(ObjectPointerVisitor* visitor,
   visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&active_exception_));
   visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&active_stacktrace_));
   visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&sticky_error_));
-  visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&async_stack_trace_));
   visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&ffi_callback_code_));
 
   // Visit the api local scope as it has all the api local handles.
diff --git a/runtime/vm/thread.h b/runtime/vm/thread.h
index 9cabac71bbb..cc3c410dfd7 100644
--- a/runtime/vm/thread.h
+++ b/runtime/vm/thread.h
@@ -657,13 +657,6 @@ class Thread : public ThreadState {
   void ClearStickyError();
   DART_WARN_UNUSED_RESULT ErrorPtr StealStickyError();
 
-  StackTracePtr async_stack_trace() const;
-  void set_async_stack_trace(const StackTrace& stack_trace);
-  void clear_async_stack_trace();
-  static intptr_t async_stack_trace_offset() {
-    return OFFSET_OF(Thread, async_stack_trace_);
-  }
-
 #if defined(DEBUG)
 #define REUSABLE_HANDLE_SCOPE_ACCESSORS(object)                                \
   void set_reusable_##object##_handle_scope_active(bool value) {               \
@@ -922,7 +915,6 @@ class Thread : public ThreadState {
   MarkingStackBlock* marking_stack_block_;
   MarkingStackBlock* deferred_marking_stack_block_;
   uword volatile vm_tag_;
-  StackTracePtr async_stack_trace_;
   // Memory location dedicated for passing unboxed int64 values from
   // generated code to runtime.
   // TODO(dartbug.com/33549): Clean this up when unboxed values
diff --git a/sdk/lib/_internal/vm/lib/async_patch.dart b/sdk/lib/_internal/vm/lib/async_patch.dart
index 8659e793b7f..88166751b24 100644
--- a/sdk/lib/_internal/vm/lib/async_patch.dart
+++ b/sdk/lib/_internal/vm/lib/async_patch.dart
@@ -265,27 +265,5 @@ void _completeOnAsyncError(
   }
 }
 
-/// Returns a [StackTrace] object containing the synchronous prefix for this
-/// asynchronous method.
-//
-// This method is recognized. It performs a runtime call if
-// FLAG_causal_async_stacks is enabled or returns `null` otherwise.
-@pragma("vm:recognized", "other")
-@pragma("vm:prefer-inline")
-Object _asyncStackTraceHelper(Function async_op)
-    native "StackTrace_asyncStackTraceHelper";
-
-// This method is asm intrinsified.
-@pragma("vm:recognized", "asm-intrinsic")
-@pragma("vm:entry-point", "call")
-void _clearAsyncThreadStackTrace()
-    native "StackTrace_clearAsyncThreadStackTrace";
-
-// This method is asm intrinsified.
-@pragma("vm:recognized", "asm-intrinsic")
-@pragma("vm:entry-point", "call")
-void _setAsyncThreadStackTrace(StackTrace stackTrace)
-    native "StackTrace_setAsyncThreadStackTrace";
-
 void _moveNextDebuggerStepCheck(Function async_op)
     native "AsyncStarMoveNext_debuggerStepCheck";
diff --git a/tests/language/vm/causal_async_exception_stack2_test.dart b/tests/language/vm/causal_async_exception_stack2_test.dart
index 14c1efbe9a9..e3ddda0f735 100644
--- a/tests/language/vm/causal_async_exception_stack2_test.dart
+++ b/tests/language/vm/causal_async_exception_stack2_test.dart
@@ -1,9 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'package:async_helper/async_minitest.dart';
 
diff --git a/tests/language/vm/causal_async_exception_stack_test.dart b/tests/language/vm/causal_async_exception_stack_test.dart
index f4421c286b4..e9df0a7aad1 100644
--- a/tests/language/vm/causal_async_exception_stack_test.dart
+++ b/tests/language/vm/causal_async_exception_stack_test.dart
@@ -1,6 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
+//
+// VMOptions=--lazy-async-stacks
 
 import 'package:async_helper/async_minitest.dart';
 
@@ -34,8 +36,8 @@ main() async {
     } catch (e, st) {
       expect(
           h.stringContainsInOrder(st.toString(), [
-            'thrower', '.dart:10', // no auto-format.
-            'generator', '.dart:19', // no auto-format.
+            'thrower', '.dart:12', // no auto-format.
+            'generator', '.dart:21', // no auto-format.
             '<asynchronous suspension>', // no auto-format.
             'foo', '.dart', // no auto-format.
             'main',
@@ -72,8 +74,8 @@ main() async {
     } catch (e, st) {
       expect(
           h.stringContainsInOrder(st.toString(), [
-            'thrower', '.dart:10', // no auto-format.
-            'main.<anonymous closure>', '.dart:71', // no auto-format.
+            'thrower', '.dart:12', // no auto-format.
+            'main.<anonymous closure>', '.dart:73', // no auto-format.
           ]),
           isTrue);
     }
diff --git a/tests/language_2/vm/causal_async_exception_stack2_test.dart b/tests/language_2/vm/causal_async_exception_stack2_test.dart
index 14c1efbe9a9..e3ddda0f735 100644
--- a/tests/language_2/vm/causal_async_exception_stack2_test.dart
+++ b/tests/language_2/vm/causal_async_exception_stack2_test.dart
@@ -1,9 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-
-// VMOptions=--causal-async-stacks --no-lazy-async-stacks
-// VMOptions=--no-causal-async-stacks --lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import 'package:async_helper/async_minitest.dart';
 
diff --git a/tests/language_2/vm/causal_async_exception_stack_test.dart b/tests/language_2/vm/causal_async_exception_stack_test.dart
index f4421c286b4..e9df0a7aad1 100644
--- a/tests/language_2/vm/causal_async_exception_stack_test.dart
+++ b/tests/language_2/vm/causal_async_exception_stack_test.dart
@@ -1,6 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
+//
+// VMOptions=--lazy-async-stacks
 
 import 'package:async_helper/async_minitest.dart';
 
@@ -34,8 +36,8 @@ main() async {
     } catch (e, st) {
       expect(
           h.stringContainsInOrder(st.toString(), [
-            'thrower', '.dart:10', // no auto-format.
-            'generator', '.dart:19', // no auto-format.
+            'thrower', '.dart:12', // no auto-format.
+            'generator', '.dart:21', // no auto-format.
             '<asynchronous suspension>', // no auto-format.
             'foo', '.dart', // no auto-format.
             'main',
@@ -72,8 +74,8 @@ main() async {
     } catch (e, st) {
       expect(
           h.stringContainsInOrder(st.toString(), [
-            'thrower', '.dart:10', // no auto-format.
-            'main.<anonymous closure>', '.dart:71', // no auto-format.
+            'thrower', '.dart:12', // no auto-format.
+            'main.<anonymous closure>', '.dart:73', // no auto-format.
           ]),
           isTrue);
     }
diff --git a/tests/standalone/causal_async_stack_test.dart b/tests/standalone/causal_async_stack_test.dart
index 5b44becbd1c..652edb3e208 100644
--- a/tests/standalone/causal_async_stack_test.dart
+++ b/tests/standalone/causal_async_stack_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--causal_async_stacks --no-lazy-async-stacks
-// VMOptions=--no-causal_async_stacks --lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import "package:expect/expect.dart";
 
diff --git a/tests/standalone/dart_developer_disabled_env_test.dart b/tests/standalone/dart_developer_disabled_env_test.dart
deleted file mode 100644
index 1d9653baa41..00000000000
--- a/tests/standalone/dart_developer_disabled_env_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no_causal_async_stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect.isFalse(
-      const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tests/standalone/dart_developer_env2_test.dart b/tests/standalone/dart_developer_env2_test.dart
deleted file mode 100644
index 881880a3c43..00000000000
--- a/tests/standalone/dart_developer_env2_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect.isFalse(
-      const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tests/standalone/dart_developer_env_test.dart b/tests/standalone/dart_developer_env_test.dart
deleted file mode 100644
index abb7bf6c0d4..00000000000
--- a/tests/standalone/dart_developer_env_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-lazy-async-stacks --causal-async-stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect
-      .isTrue(const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tests/standalone_2/causal_async_stack_test.dart b/tests/standalone_2/causal_async_stack_test.dart
index 5b44becbd1c..652edb3e208 100644
--- a/tests/standalone_2/causal_async_stack_test.dart
+++ b/tests/standalone_2/causal_async_stack_test.dart
@@ -1,8 +1,8 @@
 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// VMOptions=--causal_async_stacks --no-lazy-async-stacks
-// VMOptions=--no-causal_async_stacks --lazy-async-stacks
+//
+// VMOptions=--lazy-async-stacks
 
 import "package:expect/expect.dart";
 
diff --git a/tests/standalone_2/dart_developer_disabled_env_test.dart b/tests/standalone_2/dart_developer_disabled_env_test.dart
deleted file mode 100644
index 1d9653baa41..00000000000
--- a/tests/standalone_2/dart_developer_disabled_env_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no_causal_async_stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect.isFalse(
-      const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tests/standalone_2/dart_developer_env2_test.dart b/tests/standalone_2/dart_developer_env2_test.dart
deleted file mode 100644
index 881880a3c43..00000000000
--- a/tests/standalone_2/dart_developer_env2_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--lazy-async-stacks --no-causal-async-stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect.isFalse(
-      const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tests/standalone_2/dart_developer_env_test.dart b/tests/standalone_2/dart_developer_env_test.dart
deleted file mode 100644
index abb7bf6c0d4..00000000000
--- a/tests/standalone_2/dart_developer_env_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--no-lazy-async-stacks --causal-async-stacks
-
-import "package:expect/expect.dart";
-
-main() {
-  Expect
-      .isTrue(const bool.fromEnvironment('dart.developer.causal_async_stacks'));
-}
diff --git a/tools/bots/flutter/compile_flutter.sh b/tools/bots/flutter/compile_flutter.sh
index 1843abb2e16..8f4f2d6cbb9 100755
--- a/tools/bots/flutter/compile_flutter.sh
+++ b/tools/bots/flutter/compile_flutter.sh
@@ -82,7 +82,6 @@ $checkout/tools/sdks/dart-sdk/bin/dart \
     $checkout/pkg/front_end/tool/_fasta/compile_platform.dart \
     dart:core \
     -Ddart.vm.product=false \
-    -Ddart.developer.causal_async_stacks=true \
     -Ddart.isVM=true \
     --enable-experiment=non-nullable \
     --nnbd-agnostic \