More improvements to DeclarationResolver.

pkg/analyzer/test/src/context/context_test.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.test.src.context.context_test;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 5239 matching lines @@
    */
   void expectNoDifferences() {
     if (overwrittenCount > 0) {
       fail('Found $overwrittenCount overwritten elements.$buffer');
     }
   }
 
   @override
   void visitElement(Element element) {
     Element previousElement = previousElements[element];
-    if (!identical(previousElement, element)) {
+    bool expectIdentical = element is! LocalVariableElement;
+    bool ok = expectIdentical
+        ? identical(previousElement, element)
+        : previousElement == element;
+    if (!ok) {
       if (overwrittenCount == 0) {
         buffer.writeln();
       }
       overwrittenCount++;
       buffer.writeln('Overwritten element:');
       Element currentElement = element;
       while (currentElement != null) {
         buffer.write('  ');
         buffer.writeln(currentElement.toString());
         currentElement = currentElement.enclosingElement;
@@ skipping 18 matching lines @@
    * Initialize the visitor.
    */
   _ElementGatherer();
 
   @override
   void visitElement(Element element) {
     elements[element] = element;
     super.visitElement(element);
   }
 }