Fix for linked position offsets when insert directly before.

pkg/analysis_server/lib/src/services/correction/fix_internal.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 analysis_server.src.services.correction.fix_internal;
 
 import 'dart:collection';
 
 import 'package:analysis_server/edit/fix/fix_core.dart';
 import 'package:analysis_server/edit/fix/fix_dart.dart';
@@ skipping 1870 matching lines @@
     SourceEdit edit = new SourceEdit(offset, 0, text);
     _addEdit(target, edit);
   }
 
   /**
    * Adds a single linked position to [groupId].
    */
   void _addLinkedPosition(String groupId, SourceBuilder sb, SourceRange range) {
     // prepare offset
     int offset = range.offset;
-    if (sb.offset < offset) {
+    if (sb.offset <= offset) {
       int delta = sb.length;
       offset += delta;
     }
     // prepare group
     LinkedEditGroup group = _getLinkedPosition(groupId);
     // add position
     Position position = new Position(file, offset);
     group.addPosition(position, range.length);
   }
 
@@ skipping 600 matching lines @@
 /**
  * Describes the location for a newly created [FieldDeclaration].
  */
 class _FieldLocation {
   final String prefix;
   final int offset;
   final String suffix;
 
   _FieldLocation(this.prefix, this.offset, this.suffix);
 }