Implement latest rules prohibiting some self referencing typedefs.

tests/language/function_type_alias7_test.dart

Index: tests/language/function_type_alias7_test.dart
===================================================================
--- tests/language/function_type_alias7_test.dart	(revision 7523)
+++ tests/language/function_type_alias7_test.dart	(working copy)
@@ -1,14 +0,0 @@
-// 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.
-// Dart test for self referencing function type alias.
-
-typedef A(B x);
-typedef B(A x);
-
-main() {
-  var aFunc = _(B x) { };
-  var bFunc = _(A x) { };
-  Expect.isTrue(aFunc is A);
-  Expect.isTrue(bFunc is B);
-}