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

pkg/compiler/lib/src/js_emitter/model.dart

 // Copyright (c) 2014, 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 dart2js.new_js_emitter.model;
 
 import '../js/js.dart' as js show Expression;
 import '../constants/values.dart' show ConstantValue;
 
 class Program {
@@ skipping 167 matching lines @@
   final String name;
   final js.Expression code;
   Method(this.name, this.code);
 }
 
 class StaticMethod extends Method {
   final Holder holder;
   StaticMethod(String name, this.holder, js.Expression code)
       : super(name, code);
 }