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

tests/isolate/src/TestFramework.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.
 
 #library("TestFramework");
 #import("dart:coreimpl");
+#import("dart:isolate");
 
 
 typedef void AsynchronousTestFunction(TestExpectation check);
 
 
 void runTests(List tests, [bool guarded = true]) {
   TestRunner runner = new TestRunner(new TestSuite(tests), guarded);
   TestResult result = new TestResult(runner);
   runner.run(result);
 }
@@ skipping 248 matching lines @@
   void performTest() {
     Expect.fail('performTest called in AsynchronousTestCase');
   }
 
   AsynchronousTestFunction test;
 
   static int running = 0;
   static ReceivePort keepalive = null;
 
 }