test rename overhaul: step 8 - language tests

tests/language/hello_script_test.dart

 #! This is currently only a comment.
 // 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.
 
 // Testing a simple script importing a library.
 // This file contains the script (aka root library).
 
 #library("HelloScriptTest.dart");
-#import("HelloScriptLib.dart");
+#import("hello_script_lib.dart");
 
 main() {
   HelloLib.doTest();
   Expect.equals(18, x);
   print("Hello done.");
 }