Implement latest rules prohibiting some self referencing typedefs.

tests/language/function_type_alias5_test.dart

Index: tests/language/function_type_alias5_test.dart
===================================================================
--- tests/language/function_type_alias5_test.dart	(revision 7523)
+++ tests/language/function_type_alias5_test.dart	(working copy)
@@ -1,10 +1,14 @@
 // 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.
+// Dart test for illegally self referencing function type alias.
 
-typedef Handle Handle(String command);
+typedef Handle Handle(String command);  /// 00: compile-time error
 
+typedef F(F x);  /// 01: compile-time error
+
+typedef A(B x);  /// 02: compile-time error
+typedef B(A x);  /// 02: continued
+
 main() {
-  Handle handle = null;
 }