Generate common types into a separate library

pkg/analysis_server/lib/src/plugin/result_merger.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:collection';
 
 import 'package:analysis_server/protocol/protocol_generated.dart'
     hide AnalysisErrorFixes;
+import 'package:analyzer_plugin/protocol/protocol_common.dart' as plugin;
 import 'package:analyzer_plugin/protocol/protocol_generated.dart' as plugin;
 import 'package:meta/meta.dart';
 
 /**
  * An object used to merge partial lists of results that were contributed by
  * plugins.
  *
  * All of the methods in this class assume that the contributions from the
  * analysis server are the first partial result in the list of partial results
  * to be merged.
@@ skipping 799 matching lines @@
     if (leftEnd < rightStart || leftStart > rightEnd) {
       return false;
     }
     if (!allowNesting) {
       return true;
     }
     return !((leftStart <= rightStart && rightEnd <= leftEnd) ||
         (rightStart <= leftStart && leftEnd <= rightEnd));
   }
 }