Eliminate old style import from language tests

tests/language/library_same_name_used_lib1.dart

Index: tests/language/library_same_name_used_lib1.dart
===================================================================
--- tests/language/library_same_name_used_lib1.dart	(revision 15598)
+++ tests/language/library_same_name_used_lib1.dart	(working copy)
@@ -2,8 +2,8 @@
 // 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('lib1');
-#import('library_same_name_used_lib2.dart', prefix:'lib2');
+library lib1;
+import 'library_same_name_used_lib2.dart' as lib2;
 
 interface X {
 }