Issue 26034#3. Fix for indexing references to synthetic fields.

pkg/analyzer/lib/src/summary/index_unit.dart

 // Copyright (c) 2016, 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 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/member.dart';
@@ skipping 189 matching lines @@
    */
   static ElementInfo newElementInfo(int unitId, Element element) {
     IndexSyntheticElementKind kind = IndexSyntheticElementKind.notSynthetic;
     if (element.isSynthetic) {
       if (element is ConstructorElement) {
         kind = IndexSyntheticElementKind.constructor;
         element = element.enclosingElement;
       } else if (element is FunctionElement && element.name == 'loadLibrary') {
         kind = IndexSyntheticElementKind.loadLibrary;
         element = element.library;
+      } else if (element is FieldElement) {
+        FieldElement field = element;
+        kind = IndexSyntheticElementKind.field;
+        element = field.getter;
+        element ??= field.setter;
       } else if (element is PropertyAccessorElement) {
         PropertyAccessorElement accessor = element;
         Element enclosing = element.enclosingElement;
         bool isEnumGetter = enclosing is ClassElement && enclosing.isEnum;
         if (isEnumGetter && accessor.name == 'index') {
           kind = IndexSyntheticElementKind.enumIndex;
           element = enclosing;
         } else if (isEnumGetter && accessor.name == 'values') {
           kind = IndexSyntheticElementKind.enumValues;
           element = enclosing;
@@ skipping 580 matching lines @@
         usedNameOffsets: nameRelations.map((r) => r.offset).toList(),
         usedNameIsQualifiedFlags:
             nameRelations.map((r) => r.isQualified).toList());
   }
 
   void defineName(String name, IndexNameKind kind, int offset) {
     _StringInfo nameInfo = pkg._getStringInfo(name);
     definedNames.add(new _DefinedNameInfo(nameInfo, kind, offset));
   }
 }