Remove more libraries directives from server

pkg/analysis_server/lib/src/services/search/search_engine.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 services.search_engine;
-
 import 'dart:async';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
  * Instances of the enum [MatchKind] represent the kind of reference that was
  * found when a match represents a reference to an element.
  */
 class MatchKind {
@@ skipping 140 matching lines @@
   /**
    * Return elements of [matches] which has not-null elements.
    *
    * When [SearchMatch.element] is not `null` we cache its value, so it cannot
    * become `null` later.
    */
   static List<SearchMatch> withNotNullElement(List<SearchMatch> matches) {
     return matches.where((match) => match.element != null).toList();
   }
 }