isolates refactor: this change introduces 'dart:isolate' as a library. This is a

tests/isolate/src/Message2Test.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.
 
 // Dart test program for testing serialization of messages.
 // VMOptions=--enable_type_checks --enable_asserts
 
 #library('Message2Test');
+#import("dart:isolate");
 #import("TestFramework.dart");
 
 // ---------------------------------------------------------------------------
 // Message passing test 2.
 // ---------------------------------------------------------------------------
 
 class MessageTest {
   static void mapEqualsDeep(Map expected, Map actual) {
     Expect.equals(true, expected is Map);
     Expect.equals(true, actual is Map);
@@ skipping 48 matching lines @@
       MessageTest.mapEqualsDeep(m, received);
       remote.send(-1, null);
       expect.succeeded();
     }));
   });
 }
 
 main() {
   runTests([test]);
 }