Make elements/names.dart its own library

pkg/compiler/lib/src/serialization/modelz.dart

 // Copyright (c) 2015, 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.
 
 /// Implementation of the element model used for deserialiation.
 ///
 /// These classes are created by [ElementDeserializer] triggered by the
 /// [Deserializer].
 
 library dart2js.serialization.modelz;
 
 import '../common.dart';
 import '../common/resolution.dart' show Resolution;
 import '../constants/constructors.dart';
 import '../constants/expressions.dart';
 import '../elements/resolution_types.dart';
 import '../elements/common.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/modelx.dart' show FunctionSignatureX;
+import '../elements/names.dart';
 import '../elements/visitor.dart';
 import '../io/source_file.dart';
 import '../ordered_typeset.dart';
 import '../resolution/class_members.dart' as class_members;
 import '../resolution/scope.dart' show Scope;
 import '../resolution/tree_elements.dart' show TreeElements;
 import '../script.dart';
 import '../serialization/constant_serialization.dart';
 import 'package:front_end/src/fasta/scanner.dart' show Token;
 import '../tree/tree.dart';
@@ skipping 2380 matching lines @@
   }
 
   @override
   Node get node => throw new UnsupportedError('${this}.node');
 
   @override
   bool get hasNode => false;
 
   String toString() => 'MetadataAnnotationZ(${constant.toDartText()})';
 }