Revert "Switch libraries to using new tags."

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;
-
 // TODO: Convert this abstract class into a concrete class double
 // that uses the patch class functionality to account for the
 // different platform implementations.
 
 /**
  * Representation of Dart doubles containing double specific constants
  * and operations and specializations of operations inherited from
  * [num].
  *
  * The [double] type is contagious. Operations on [double]s return
@@ skipping 79 matching lines @@
    * Accepts the same format as double literals:
    *   [: ['+'|'-'] [digit* '.'] digit+ [('e'|'E') ['+'|'-'] digit+] :]
    *
    * Also recognizes "NaN", "Infinity" and "-Infinity" as inputs and
    * returns the corresponding double value.
    *
    * Throws a [FormatException] if [source] is not a valid double literal.
    */
   external static double parse(String source);
 }