Make elements/names.dart its own library

pkg/compiler/lib/src/universe/selector.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.
 
 library dart2js.selector;
 
 import '../common.dart';
 import '../common/names.dart' show Names;
-import '../elements/elements.dart'
-    show Element, Elements, FunctionSignature, Name, PublicName;
+import '../elements/elements.dart' show Element, Elements, FunctionSignature;
 import '../elements/entities.dart';
+import '../elements/names.dart';
 import '../util/util.dart' show Hashing;
 import 'call_structure.dart' show CallStructure;
 
 class SelectorKind {
   final String name;
   final int hashCode;
   const SelectorKind(this.name, this.hashCode);
 
   static const SelectorKind GETTER = const SelectorKind('getter', 0);
   static const SelectorKind SETTER = const SelectorKind('setter', 1);
@@ skipping 232 matching lines @@
     // Add bits from the call structure.
     return Hashing.mixHashCodeBits(hash, callStructure.hashCode);
   }
 
   String toString() {
     return 'Selector($kind, $name, ${callStructure.structureToString()})';
   }
 
   Selector toCallSelector() => new Selector.callClosureFrom(this);
 }