Fix a bug in allocation sinking and load elimination.

tests/language/allocation_sinking_vm_test.dart

 // Copyright (c) 2013, 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.
 // Test allocation sinking optimization.
 
 import 'package:expect/expect.dart';
 
 class Point {
   var x, y;
 
@@ skipping 85 matching lines @@
   var a = new A<int>();
   a.x = x;
   a.y = x;
   if (x is int) return a.x + a.y;
   Expect.isFalse(a is A<double>);
   Expect.isTrue(a is A<int>);
   Expect.isTrue(a is A);
   return a.x - a.y;
 }
 
+class WithFinal {
+  final _x;
+  WithFinal(this._x);
+}
+
+testInitialValueForFinalField(x) {
+  new WithFinal(x);
+}
+
+testFinalField() {
+  for (var i = 0; i < 10000; i++) {
+   testInitialValueForFinalField(1);
+  }
+}
+
+class V {
+  var x = 0;
+}
+
+test_vm_field() {
+  var obj;
+  inner() => obj.x = 42;
+  var a = new V();
+  obj = a;
+  var t1 = a.x;
+  var t2 = inner();
+  return a.x + t1 + t2;
+}
+
+testVMField() {
+  Expect.equals(84, test_vm_field());
+  for (var i=0; i<15000; i++) test_vm_field();
+  Expect.equals(84, test_vm_field());
+}
+
 main() {
   var c = new C(new Point(0.1, 0.2));
 
   // Compute initial values.
   final x0 = test1(c, 11.11, 22.22);
   final y0 = testForwardingThroughEffects(c, 11.11, 22.22);
   final z0 = testIdentity(c.p);
 
   // Force optimization.
   for (var i = 0; i < 10000; i++) {
@@ skipping 24 matching lines @@
   Expect.equals(6008, (y2 * 100).floor());
   Expect.equals(y0, y1);
   Expect.equals(y0, y2);
 
   // Test that identity of materialized objects is preserved correctly and
   // no copies are materialized.
   final z1 = testIdentity(c.p);
   final z2 = testIdentity(new F(c.p));
   Expect.equals(z0, z1);
   Expect.equals(z0, z2);
+
+  testFinalField();
+  testVMField();
 }