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

tests/language/src/TypedMessageTest.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 isolate communication with
 // typed objects.
 // VMOptions=--enable_type_checks --enable_asserts
 
+#library("TypedMessageTest");
+#import("dart:isolate");
+
 class TypedMessageTest {
   static void testMain() {
     LogClient.test();
   }
 }
 
 
 class LogClient {
   static void test() {
     new LogIsolate().spawn().then((SendPort remote) {
@@ skipping 27 matching lines @@
       this.port.close();
       replyTo.send(1, null);
       print("Stopping log server.");
     });
   }
 }
 
 main() {
   TypedMessageTest.testMain();
 }