Revert r23380, some browser tests fail.

tests/language/local_function_non_equal_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.
-
-import "package:expect/expect.dart";
-
-foo() => () => 42;
-bar() {
-  var c = () => 54;
-  return c;
-}
-baz() {
-  c() => 68;
-  return c;
-}
-
-main() {
-  var first = foo();
-  var second = foo();
-  Expect.isFalse(identical(first, second));
-  Expect.notEquals(first, second);
-
-  first = bar();
-  second = bar();
-  Expect.isFalse(identical(first, second));
-  Expect.notEquals(first, second);
-
-  first = baz();
-  second = baz();
-  Expect.isFalse(identical(first, second));
-  Expect.notEquals(first, second);
-}