Move dart2js from sdk/lib/_internal/compiler to pkg/compiler

pkg/compiler/lib/src/mirror_renamer/mirror_renamer.dart

 // Copyright (c) 2013, 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 mirror_renamer;
 
 import '../dart2jslib.dart' show Script, Compiler;
 import '../tree/tree.dart';
 import '../scanner/scannerlib.dart' show Token;
 import '../elements/elements.dart';
 import '../dart_backend/dart_backend.dart' show DartBackend,
                                                 PlaceholderCollector;
 
 part 'renamer.dart';
 
 class MirrorRenamer {
   const MirrorRenamer();
 
   LibraryElement get helperLibrary => null;
 
   FunctionElement get getNameFunction => null;
 
   bool isMirrorHelperLibrary(LibraryElement element) => false;
 
   void registerStaticSend(Element currentElement, Element target, Node node) {}
 
   void addRenames(Map<Node, String> renames, List<Node> topLevelNodes,
                   PlaceholderCollector placeholderCollector) {}
 }