Fix bug with guarded fields and deserialization.

tests/language/vm/optimized_guarded_field_isolates_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.
+// VMOptions=--optimization_counter_threshold=100
+
+// Test field type tracking and field list-length tracking in the presence of
+// multiple isolates.
+
+import "dart:isolate";
+import "package:expect/expect.dart";
+
+class A {
+  A(this.a);
+  var a;
+}
+
+class B extends A {
+  B(a, this.b) : super(a) { }
+
+  var b;
+}
+
+f1(SendPort send_port) {
+  send_port.send(new B("foo", "bar"));
+}
+
+test_b(B obj) => obj.a + obj.b;
+
+test_field_type() {
+  var receive_port = new ReceivePort();
+  Future<Isolate> isolate = Isolate.spawn(f1, receive_port.sendPort);
+  B b = new B(1, 2);
+  for (var i = 0; i < 200; i++) test_b(b);
+  Expect.equals(3, test_b(b));
+  Future<B> item = receive_port.first;
+  item.then((B value) {
+      Expect.equals("foobar", test_b(value));
+      receive_port.close();
+  });
+}
+
+class C {
+  C(this.list);
+  final List list;
+}
+
+f2(SendPort send_port) {
+  send_port.send(new C(new List(1)));
+}
+
+test_c(C obj) => obj.list[9999];
+
+test_list_length() {
+  var receive_port = new ReceivePort();
+  Future<Isolate> isolate = Isolate.spawn(f2, receive_port.sendPort);
+  List list = new List(10000);
+  C c = new C(new List(10000));
+  for (var i = 0; i < 200; i++) test_c(c);
+  Expect.equals(null, test_c(c));
+  Future<C> item = receive_port.first;
+  item.then((C value) {
+      Expect.throws(() => test_c(value), (e) => e is RangeError);
+      receive_port.close();
+  });
+}
+
+main() {
+  test_field_type();
+  test_list_length();
+}