Create and use new change/depends flags for the GVN analysis.

lib/compiler/implementation/ssa/builder.dart

 // Copyright (c) 2012, 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.
 
 class Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2181 matching lines @@
                                                   HInstruction receiver,
                                                   HInstruction value) {
     assert(Elements.isInstanceSend(send, elements));
     Selector selector = elements.getSelector(send);
     assert(selector.isSetter());
     SourceString setterName = selector.name;
     Element staticInterceptor = null;
     if (methodInterceptionEnabled) {
       staticInterceptor = interceptors.getStaticSetInterceptor(setterName);
     }
+    bool hasSetter = compiler.world.hasAnyUserDefinedSetter(selector);
     if (staticInterceptor != null) {
       HStatic target = new HStatic(staticInterceptor);
       add(target);
       List<HInstruction> inputs = <HInstruction>[target, receiver, value];
       addWithPosition(new HInvokeInterceptor(selector, inputs), send);
     } else {
-      addWithPosition(new HInvokeDynamicSetter(selector, null, receiver, value),
-                      send);
+      addWithPosition(
+          new HInvokeDynamicSetter(selector, null, receiver, value, !hasSetter),
+          send);
     }
     stack.add(value);
   }
 
   void generateSetter(SendSet send, Element element, HInstruction value) {
     if (Elements.isStaticOrTopLevelField(element)) {
       if (element.isSetter()) {
         HStatic target = new HStatic(element);
         add(target);
         addWithPosition(new HInvokeStatic(<HInstruction>[target, value]), send);
@@ skipping 2176 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }