sdk files reorganization to make dart2js a proper package

pkg/compiler/lib/src/patch_parser.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.
 
 /**
  * This library contains the infrastructure to parse and integrate patch files.
  *
  * Three types of elements can be patched: [LibraryElement], [ClassElement],
  * [FunctionElement]. Patches are introduced in patch libraries which are loaded
  * together with the corresponding origin library. Which libraries that are
  * patched is determined by the dart2jsPatchPath field of LibraryInfo found
- * in [:lib/_internal/libraries.dart:].
+ * in [:lib/_internal/sdk_library_metadata/lib/libraries.dart:].
  *
  * Patch libraries are parsed like regular library and thus provided with their
  * own elements. These elements which are distinct from the elements from the
  * patched library and the relation between patched and patch elements is
  * established through the [:patch:] and [:origin:] fields found on
  * [LibraryElement], [ClassElement] and [FunctionElement]. The [:patch:] fields
  * are set on the patched elements to point to their corresponding patch
  * element, and the [:origin:] elements are set on the patch elements to point
  * their corresponding patched elements.
  *
@@ skipping 545 matching lines @@
 
 class PatchVersion {
   final String tag;
 
   const PatchVersion(this.tag);
 
   bool isActive(String patchTag) => tag == null || tag == patchTag;
 
   String toString() => 'PatchVersion($tag)';
 }