Updates the corelib to the new default specification for interfaces and new factory syntax

corelib/src/isolate.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 core library.
 
 /**
  * [SendPort]s are created from [ReceivePort]s. Any message sent through
  * a [SendPort] is delivered to its respective [ReceivePort]. There might be
  * many [SendPort]s for the same [ReceivePort].
@@ skipping 36 matching lines @@
 
 /**
  * [ReceivePort]s, together with [SendPort]s, are the only means of
  * communication between isolates. [ReceivePort]s have a [:toSendPort:] method
  * which returns a [SendPort]. Any message that is sent through this [SendPort]
  * is delivered to the [ReceivePort] it has been created from. There, they are
  * dispatched to the callback that has been registered on the receive port.
  *
  * A [ReceivePort] may have many [SendPort]s.
  */
-interface ReceivePort factory ReceivePortFactory {
+interface ReceivePort default ReceivePortFactory {
 
   /**
    * Opens a long-lived port for receiving messages. The returned port
    * must be explicitly closed through [ReceivePort.close].
    */
   ReceivePort();
 
   /**
    * Opens a single-shot reply port. Once a message has been received
    * on this port, it is automatically closed -- obviously without
@@ skipping 103 matching lines @@
   /**
    * When isolates are created, an instance of the template's class is
    * instantiated in the new isolate. After the [port] has been set up, this
    * [main] method is invoked on the instance.
    */
   abstract void main();
 
   final bool _isLight;
   ReceivePort _port;
 }