Update or delete language tests using obsolete interfaces or default factory

tests/language/library_same_name_used_lib2.dart

Index: tests/language/library_same_name_used_lib2.dart
===================================================================
--- tests/language/library_same_name_used_lib2.dart	(revision 15648)
+++ tests/language/library_same_name_used_lib2.dart	(working copy)
@@ -1,9 +1,9 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 library lib2;
-import 'library_same_name_used_lib1.dart' as lib1;  // for interface X.
+import 'library_same_name_used_lib1.dart' as lib1;  // for abstract class X.
 
 class X implements lib1.X {
   X();