[dart2js] Fix side-effects bugs

Make the `HInstruction.sideEffects` field final.  The instruction owns
the mutable SideEffects objects so it would be dangerous to make the
field reference a shared SideEffects object.

Update the side effects of an interface call when the target becomes
known. We were essentially missing any benefit of inferred
side-effects for instance members.

Change-Id: I46da1d87e166864cd7fa4cee01f209bcc19986af
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/430546
Commit-Queue: Stephen Adams <sra@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>

pkg/compiler/lib/src/ssa/builder.dart

@@ -6775,7 +6775,9 @@ class KernelSsaGraphBuilder extends ir.VisitorDefault<void>
         _currentImplicitInstantiations,
       );
     }
-    instruction.sideEffects = _inferredData.getSideEffectsOfElement(target);
+    instruction.sideEffects.setTo(
+      _inferredData.getSideEffectsOfElement(target),
+    );
     instruction.allowCSE = closedWorld.annotationsData.allowCSE(target);
     instruction.allowDCE = closedWorld.annotationsData.allowDCE(target);
     push(instruction);
@@ -7391,9 +7393,8 @@ class KernelSsaGraphBuilder extends ir.VisitorDefault<void>
       isSetter: selector.isSetter || selector.isIndexSet,
     );
     // TODO(natebiggs): Pass typeMask below and make non-nullable.
-    instruction.sideEffects = _inferredData.getSideEffectsOfSelector(
-      selector,
-      null,
+    instruction.sideEffects.setTo(
+      _inferredData.getSideEffectsOfSelector(selector, null),
     );
     push(instruction);
     return instruction;

pkg/compiler/lib/src/ssa/nodes.dart

@@ -1172,7 +1172,7 @@ abstract class HInstruction implements SpannableWithEntity {
   /// Type of the instruction.
   late AbstractValue instructionType;
 
-  SideEffects sideEffects = SideEffects.empty();
+  final SideEffects sideEffects = SideEffects.empty();
   bool _useGvn = false;
 
   // TODO(sra): Consider whether to reduce instruction size by collecting all
@@ -3516,7 +3516,8 @@ class HThrowExpression extends HInstruction {
 
 class HAwait extends HInstruction {
   HAwait(super.value, super.type) : super._oneInput() {
-    sideEffects = SideEffects();
+    sideEffects.setAllSideEffects();
+    sideEffects.setDependsOnSomething();
   }
   @override
   String toString() => 'await';
@@ -3535,7 +3536,8 @@ class HYield extends HInstruction {
     SourceInformation? sourceInformation,
   ) : super._oneInput() {
     this.sourceInformation = sourceInformation;
-    sideEffects = SideEffects();
+    sideEffects.setAllSideEffects();
+    sideEffects.setDependsOnSomething();
   }
   bool hasStar;
   @override

pkg/compiler/lib/src/ssa/optimize.dart

@@ -1071,6 +1071,9 @@ class SsaInstructionSimplifier extends HBaseVisitor<HInstruction>
         node.element = method;
       }
 
+      node.sideEffects.restrictTo(
+        _globalInferenceResults.inferredData.getSideEffectsOfElement(element),
+      );
       if (_closedWorld.annotationsData.allowCSE(element)) {
         node.allowCSE = true;
       }
@@ -2035,6 +2038,9 @@ class SsaInstructionSimplifier extends HBaseVisitor<HInstruction>
         if (_nativeData.isNativeMember(member)) {
           return tryInlineNativeGetter(node, member) ?? node;
         }
+        node.sideEffects.restrictTo(
+          _globalInferenceResults.inferredData.getSideEffectsOfElement(member),
+        );
         if (_closedWorld.annotationsData.allowCSE(member)) {
           node.allowCSE = true;
         }

pkg/compiler/lib/src/universe/side_effects.dart

@@ -184,6 +184,10 @@ class SideEffects {
     _flags = other._flags;
   }
 
+  void restrictTo(SideEffects other) {
+    _flags = _flags.intersection(other._flags);
+  }
+
   @override
   String toString() {
     StringBuffer buffer = StringBuffer();