Fix Queue's iterator to allocate an iterator using type parameter. Enable now passing tests.

sdk/lib/collection/queue.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.
 
 part of dart.collection;
 
 /**
  * A [Queue] is a collection that can be manipulated at both ends. One
  * can iterate over the elements of a queue through [forEach] or with
  * an [Iterator].
@@ skipping 369 matching lines @@
       queue._table.setRange(0, length, sourceList, 0);
       queue._tail = length;
       return queue;
     } else {
       return new ListQueue<E>()..addAll(source);
     }
   }
 
   // Iterable interface.
 
-  Iterator<E> get iterator => new _ListQueueIterator(this);
+  Iterator<E> get iterator => new _ListQueueIterator<E>(this);
 
   void forEach(void action (E element)) {
     int modificationCount = _modificationCount;
     for (int i = _head; i != _tail; i = (i + 1) & (_table.length - 1)) {
       action(_table[i]);
       _checkModification(modificationCount);
     }
   }
 
   bool get isEmpty => _head == _tail;
@@ skipping 298 matching lines @@
     _queue._checkModification(_modificationCount);
     if (_position == _end) {
       _current = null;
       return false;
     }
     _current = _queue._table[_position];
     _position = (_position + 1) & (_queue._table.length - 1);
     return true;
   }
 }