Use relative URIs for core library part-of statements.

sdk/lib/core/double.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.
 
-part of dart.core;
+part of "core.dart";
 
 // TODO: Convert this abstract class into a concrete class double
 // that uses the patch class functionality to account for the
 // different platform implementations.
 
 /**
  * A double-precision floating point number.
  *
  * Representation of Dart doubles containing double specific constants
  * and operations and specializations of operations inherited from
@@ skipping 180 matching lines @@
    *     "  3.14 \xA0"
    *     "0."
    *     ".0"
    *     "-1.e3"
    *     "1234E+7"
    *     "+.12e-9"
    *     "-NaN"
    */
   external static double parse(String source, [double onError(String source)]);
 }