Fix equality of implicit closures in the Dart VM.

runtime/lib/function.dart

Index: runtime/lib/function.dart
===================================================================
--- runtime/lib/function.dart	(revision 0)
+++ runtime/lib/function.dart	(revision 0)
@@ -0,0 +1,10 @@
+// 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.
+
+class _FunctionImpl implements Function {
+
+  bool operator ==(other) native "FunctionImpl_equals";
+
+  int get hashCode native "FunctionImpl_hashCode";
+}