Move libraries.dart to lib/_internal/libraries.dart .

lib/_internal/libraries.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.
 
 #library('libraries');
 
 /**
  * Mapping of "dart:" library name (e.g. "core") to information about that library.
  * This information is structured such that Dart Editor can parse this file
  * and extract the necessary information without executing it
@@ skipping 121 matching lines @@
    * and that tools like Dart Editor should not show these libraries
    * in a list of all libraries unless the user specifically asks the tool to do so.
    * (e.g. "coreimpl" contains implementation for the "core" library).
    */
   final bool implementation;
 
   const LibraryInfo(this.path, [this.category = "Shared",
            this.dart2jsPath, this.dart2jsPatchPath,
            this.implementation = false, this.internal = false]);
 }