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

pkg/compiler/lib/src/mirrors/dart2js_type_mirrors.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.
 
 part of dart2js.mirrors;
 
 abstract class ClassMirrorMixin implements ClassSourceMirror {
   bool get hasReflectedType => false;
   Type get reflectedType {
     throw new UnsupportedError("ClassMirror.reflectedType is not supported.");
@@ skipping 484 matching lines @@
     if (other is! TypeMirror) {
       return false;
     }
     return other.isDynamic;
   }
 
   int get hashCode => 13 * _type.hashCode;
 
   String toString() => 'Mirror on dynamic';
 }