Sort strings in the index.

pkg/analyzer/lib/src/summary/format.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.
 //
 // This file has been automatically generated.  Please do not edit it manually.
 // To regenerate the file, use the script "pkg/analyzer/tool/generate_files".
 
 library analyzer.src.summary.format;
 
 import 'flat_buffers.dart' as fb;
@@ skipping 1659 matching lines @@
   void set elementUnits(List<int> _value) {
     assert(!_finished);
     assert(_value == null || _value.every((e) => e >= 0));
     _elementUnits = _value;
   }
 
   @override
   List<String> get strings => _strings ??= <String>[];
 
   /**
-   * List of unique element strings used in this [PackageIndex].
+   * List of unique element strings used in this [PackageIndex].  The list is
+   * sorted in ascending order, so that the client can quickly check the
+   * presence of a string in this [PackageIndex].
    */
   void set strings(List<String> _value) {
     assert(!_finished);
     _strings = _value;
   }
 
   @override
   List<int> get unitLibraryUris => _unitLibraryUris ??= <int>[];
 
   /**
@@ skipping 6022 matching lines @@
     "propagatedTypeSlot": propagatedTypeSlot,
     "type": type,
     "visibleLength": visibleLength,
     "visibleOffset": visibleOffset,
   };
 
   @override
   String toString() => convert.JSON.encode(toJson());
 }