Reapply change to GVN all HFieldGet instructions.

lib/compiler/implementation/ssa/value_set.dart

Index: lib/compiler/implementation/ssa/value_set.dart
diff --git a/lib/compiler/implementation/ssa/value_set.dart b/lib/compiler/implementation/ssa/value_set.dart
index 9447dfdc6fe0df42679f26511ff0dd90dcce4a96..98a1d5322cff04611f24d8d43369c3f8c1ee4d74 100644
--- a/lib/compiler/implementation/ssa/value_set.dart
+++ b/lib/compiler/implementation/ssa/value_set.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -47,6 +47,7 @@ class ValueSet {
   }
 
   void kill(int flags) {
+    if (flags == 0) return;
     int depends = HInstruction.computeDependsOnFlags(flags);
     // Kill in the hash table.
     for (int index = 0, length = table.length; index < length; index++) {