Create synthetic FieldElement(s) (don't use non-synthetic ones) for non-synthetic class getters/set…

pkg/analyzer/lib/src/dart/element/builder.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 analyzer.src.dart.element.builder;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 958 matching lines @@
         }
         if (node.returnType == null) {
           element.hasImplicitReturnType = true;
         }
         _currentHolder.addMethod(element);
         methodName.staticElement = element;
       } else {
         SimpleIdentifier propertyNameNode = node.name;
         String propertyName = propertyNameNode.name;
         FieldElementImpl field =
-            _currentHolder.getField(propertyName) as FieldElementImpl;
+            _currentHolder.getField(propertyName, synthetic: true) as FieldElementImpl;
         if (field == null) {
           field = new FieldElementImpl(node.name.name, -1);
           field.final2 = true;
           field.static = isStatic;
           field.synthetic = true;
           _currentHolder.addField(field);
         }
         if (node.isGetter) {
           PropertyAccessorElementImpl getter =
               new PropertyAccessorElementImpl.forNode(propertyNameNode);
@@ skipping 467 matching lines @@
     return null;
   }
 
   /**
    * Return the lexical identifiers associated with the given [identifiers].
    */
   static List<String> _getIdentifiers(NodeList<SimpleIdentifier> identifiers) {
     return identifiers.map((identifier) => identifier.name).toList();
   }
 }