[dart2js] Fix record tracing w.r.t to closures.

We were losing track of records (and their contents) when they flowed into a closure. Now we correctly bailout when we encounter this situation.

This matches the behavior we have for tracing other collection objects.

Change-Id: I2b0945f9ab9732e3f460cefee451c7b853316ad5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/478780
Commit-Queue: Nate Biggs <natebiggs@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>

pkg/compiler/lib/src/inferrer/record_tracer.dart

@@ -1,6 +1,9 @@
 // Copyright (c) 2023, 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.
+import '../common/names.dart';
+import '../elements/entities.dart';
+
 import 'node_tracer.dart';
 import 'type_graph_nodes.dart';
 
@@ -16,4 +19,34 @@ class RecordTracerVisitor extends TracerVisitor {
     }
     return false;
   }
+
+  @override
+  void visitClosureCallSiteTypeInformation(
+    ClosureCallSiteTypeInformation info,
+  ) {
+    bailout('Passed to a closure');
+  }
+
+  @override
+  void visitStaticCallSiteTypeInformation(StaticCallSiteTypeInformation info) {
+    super.visitStaticCallSiteTypeInformation(info);
+    MemberEntity called = info.calledElement;
+    if (inferrer.closedWorld.commonElements.isForeign(called) &&
+        called.name == Identifiers.js) {
+      bailout('Used in JS ${info.debugName}');
+    }
+  }
+
+  @override
+  void visitDynamicCallSiteTypeInformation(
+    DynamicCallSiteTypeInformation info,
+  ) {
+    super.visitDynamicCallSiteTypeInformation(info);
+    final selector = info.selector!;
+    if (selector.isCall &&
+        (info.hasClosureCallTargets || dynamicCallTargetsNonFunction(info))) {
+      bailout('Passed to a closure');
+      return;
+    }
+  }
 }

tests/language/records/closure_flow_test.dart

@@ -0,0 +1,56 @@
+// Copyright (c) 2026, 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.
+
+typedef F<T> = void Function(T chunk);
+typedef A<T> = ({F<T> sendChunk, int whatever});
+
+class M {
+  final List<String> content;
+  M({required this.content});
+}
+
+class G {
+  final M _chunk;
+  G(this._chunk);
+
+  String get text => _chunk.content.join('');
+}
+
+void produceIt(A<M> ctx) {
+  int base(A<M> b) {
+    b.sendChunk(M(content: ["content-value"]));
+    return 1;
+  }
+
+  final composeModel = _values.fold(
+    base,
+    (next, mw) =>
+        (c) => mw.f(c, next),
+  );
+  composeModel((
+    whatever: 1,
+    sendChunk: (c) => ctx.sendChunk(M(content: c.content)),
+  ));
+}
+
+void useIt(G g) {
+  print(g.text);
+}
+
+class Wrapper {
+  int f(A<M> c, int Function(A<M>) next) {
+    return next(c);
+  }
+}
+
+List<Wrapper> _values = [Wrapper(), Wrapper(), Wrapper()];
+
+void main() {
+  produceIt((
+    whatever: 2,
+    sendChunk: (c) {
+      useIt(G(c));
+    },
+  ));
+}