Move JSSyntaxRegExp to core as a private member. This removes the last refrences to dart:coreimpl.

sdk/lib/html/templates/html/impl/impl_NodeList.darttemplate

 // 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.
 
 part of html;
 
 // TODO(nweiz): when all implementations we target have the same name for the
-// coreimpl implementation of List<E>, extend that rather than wrapping.
+// implementation of List<E>, extend that rather than wrapping.
 class _ListWrapper<E> implements List<E> {
   List _list;
 
   _ListWrapper(List this._list);
 
   Iterator<E> iterator() => _list.iterator();
 
   bool contains(E element) => _list.contains(element);
 
   void forEach(void f(E element)) => _list.forEach(f);
@@ skipping 151 matching lines @@
   void insertRange(int start, int rangeLength, [Node initialValue]) {
     throw new UnsupportedError("Cannot insertRange on immutable List.");
   }
   List<Node> getRange(int start, int rangeLength) =>
     new _NodeListWrapper(_Lists.getRange(this, start, rangeLength, <Node>[]));
 
   // -- end List<Node> mixins.
 
 $!MEMBERS
 }