Use relative URIs for core library part-of statements.

sdk/lib/core/iterable.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.core;
+part of "core.dart";
 
 /**
  * A collection of values, or "elements", that can be accessed sequentially.
  *
  * The elements of the iterable are accessed by getting an [Iterator]
  * using the [iterator] getter, and using it to step through the values.
  * Stepping with the iterator is done by calling [Iterator.moveNext],
  * and if the call returns `true`,
  * the iterator has now moved to the next element,
  * which is then available as [Iterator.current].
@@ skipping 629 matching lines @@
  */
 abstract class BidirectionalIterator<E> implements Iterator<E> {
   /**
    * Move back to the previous element.
    *
    * Returns true and updates [current] if successful. Returns false
    * and sets [current] to null if there is no previous element.
    */
   bool movePrevious();
 }