Make elements/names.dart its own library

pkg/compiler/lib/src/js_emitter/full_emitter/class_emitter.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 dart2js.js_emitter.full_emitter.class_emitter;
 
 import '../../common.dart';
 import '../../common/names.dart' show Names;
 import '../../elements/resolution_types.dart' show ResolutionDartType;
 import '../../deferred_load.dart' show OutputUnit;
 import '../../elements/elements.dart'
-    show ClassElement, FieldElement, MemberElement, Name;
+    show ClassElement, FieldElement, MemberElement;
+import '../../elements/names.dart';
 import '../../js/js.dart' as jsAst;
 import '../../js/js.dart' show js;
 import '../../js_backend/js_backend.dart' show CompoundName, Namer;
 import '../../universe/selector.dart' show Selector;
 import '../../util/util.dart' show equalElements;
 import '../../world.dart' show ClosedWorld;
 import '../js_emitter.dart' hide Emitter, EmitterFactory;
 import '../model.dart';
 import 'emitter.dart';
 
@@ skipping 423 matching lines @@
     String reflectionName = emitter.getReflectionName(selector, name);
     if (reflectionName != null) {
       var reflectable = js(
           backend.mirrorsData.isMemberAccessibleByReflection(member)
               ? '1'
               : '0');
       builder.addPropertyByName('+$reflectionName', reflectable);
     }
   }
 }