test rename overhaul: step 8 - language tests

tests/language/library_negative_test.dart

 // Copyright (c) 2011, 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.
 // This test should fail to load because the app file references a
 // library spec file that does not exist.
 
 #library("LibraryNegativeTest.dart");
-#import("NonexistingLibrary.lib");
+#import("nonexisting_library.lib");
 
 
 main(args) {
   LibraryNegativeTest.testMain(args);
 }
 
 class LibraryNegativeTest {
   static testMain() {
     print("Er, hello world? This should not be printed!");
   }
 }
 
 main() {
   LibraryNegativeTest.testMain();
 }