Fix type mismatch in directory listing.

runtime/bin/directory_impl.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.
 
 
 class DirectoryException {
   const DirectoryException(String this.message);
   final String message;
 }
 
@@ skipping 10 matching lines @@
              message['dirHandler'],
              message['fileHandler'],
              message['doneHandler'],
              message['dirErrorHandler']);
     });
   }
 
   void _list(String dir,
              int id,
              bool recursive,
-             ReceivePort dirHandler,
-             ReceivePort fileHandler,
-             ReceivePort doneHandler,
-             ReceivePort dirErrorHandler) native "Directory_List";
+             SendPort dirHandler,
+             SendPort fileHandler,
+             SendPort doneHandler,
+             SendPort dirErrorHandler) native "Directory_List";
 }
 
 
 class _Directory implements Directory {
 
   _Directory.open(String this._dir) {
     _id = 0;
     _closed = false;
     _listing = false;
     if (!_open(_dir)) {
@@ skipping 103 matching lines @@
   ReceivePort _dirHandler;
   ReceivePort _fileHandler;
   ReceivePort _doneHandler;
   ReceivePort _dirErrorHandler;
 
   String _dir;
   int _id;
   bool _closed;
   bool _listing;
 }