Make index provisional API.

pkg/analysis_server/lib/src/services/index/local_index.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.src.index.local_index;
 
 import 'dart:async';
 
-import 'package:analysis_server/plugin/index/index_core.dart';
+import 'package:analysis_server/src/provisional/index/index_core.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/store/split_store.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
  * A local implementation of [Index].
  */
 class LocalIndex extends Index {
@@ skipping 88 matching lines @@
   @override
   void run() {
     // NO-OP for the local index
   }
 
   @override
   void stop() {
     // NO-OP for the local index
   }
 }