Reinstall previous behavior for Set and Queue toString.

runtime/lib/array.dart

 // Copyright (c) 2012, 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.
 
 
 // TODO(srdjan): Use shared array implementation.
 class _List<E> implements List<E> {
   static final int _classId = (new _List(0))._cid;
 
   factory _List(length) native "List_allocate";
 
   E operator [](int index) native "List_getIndexed";
 
   void operator []=(int index, E value) native "List_setIndexed";
 
   String toString() {
-    return IterableMixinWorkaround.toStringIterable(this,'[' , ']');
+    return ListBase.listToString(this);
   }
 
   int get length native "List_getLength";
 
   void _copyFromObjectArray(_List src,
                             int srcStart,
                             int dstStart,
                             int count)
       native "List_copyFromObjectArray";
 
@@ skipping 408 matching lines @@
 
   void sort([int compare(E a, E b)]) {
     throw UnmodifiableListError.change();
   }
 
   void shuffle([Random random]) {
     throw UnmodifiableListError.change();
   }
 
   String toString() {
-    return IterableMixinWorkaround.toStringIterable(this, '[', ']');
+    return ListBase.listToString(this);
   }
 
   int indexOf(Object element, [int start = 0]) {
     return Lists.indexOf(this, element, start, this.length);
   }
 
   int lastIndexOf(Object element, [int start = null]) {
     if (start == null) start = length - 1;
     return Lists.lastIndexOf(this, element, start);
   }
@@ skipping 73 matching lines @@
     }
     _position = _length;
     _current = null;
     return false;
   }
 
   E get current {
     return _current;
   }
 }