Start creating a MemberSet abstraction, and use it to fold getters/setters into field accesses.

lib/compiler/implementation/ssa/nodes.dart

 // Copyright (c) 2011, 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.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
   R visitBitXor(HBitXor node);
@@ skipping 1194 matching lines @@
   }
 
   int typeCode() => 4;
   bool typeEquals(other) => other is HInvokeInterceptor;
   bool dataEquals(HInvokeInterceptor other) {
     return getter == other.getter && name == other.name;
   }
 }
 
 class HFieldGet extends HInstruction {
-  final Element element;
-  HFieldGet(Element this.element, HInstruction receiver)
+  final SourceString name;
+  HFieldGet(this.name, HInstruction receiver)
       : super(<HInstruction>[receiver]);
-  HFieldGet.fromActivation(Element this.element) : super(<HInstruction>[]);
+  HFieldGet.fromActivation(this.name) : super(<HInstruction>[]);
 
   HInstruction get receiver() => inputs.length == 1 ? inputs[0] : null;
   accept(HVisitor visitor) => visitor.visitFieldGet(this);
+
+  void prepareGvn() {
+    clearAllSideEffects();
+  }
+
+  int typeCode() => 27;
+  bool typeEquals(other) => other is HFieldGet;
+  bool dataEquals(HFieldGet other) => name == other.name;
 }
 
 class HFieldSet extends HInstruction {
-  final Element element;
-  HFieldSet(Element this.element, HInstruction receiver, HInstruction value)
+  final SourceString name;
+  HFieldSet(this.name, HInstruction receiver, HInstruction value)
       : super(<HInstruction>[receiver, value]);
-  HFieldSet.fromActivation(Element this.element, HInstruction value)
+  HFieldSet.fromActivation(this.name, HInstruction value)
       : super(<HInstruction>[value]);
 
   HInstruction get receiver() => inputs.length == 2 ? inputs[0] : null;
   HInstruction get value() => inputs.length == 2 ? inputs[1] : inputs[0];
   accept(HVisitor visitor) => visitor.visitFieldSet(this);
 
   void prepareGvn() {
     // TODO(ngeoffray): implement more fine grain side effects.
     setAllSideEffects();
   }
@@ skipping 1215 matching lines @@
                        this.catchBlock,
                        this.finallyBlock);
 
   HBasicBlock get start() => body.start;
   HBasicBlock get end() =>
       finallyBlock === null ? catchBlock.end : finallyBlock.end;
 
   bool accept(HStatementInformationVisitor visitor) =>
     visitor.visitTryInfo(this);
 }