Update or delete language tests using obsolete interfaces or default factory

tests/language/interface_static_method_negative_test.dart

-// 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.
 
-interface A {
+abstract class A {
   static void foo();
 }
 
 class InterfaceStaticMethodNegativeTest {
 
   static testMain() {
   }
 }
 
 main() {
   InterfaceStaticMethodNegativeTest.testMain();
 }