Issue 24765. Don't re-resolve already resolved variable references.

pkg/analyzer/lib/src/generated/element_resolver.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 engine.resolver.element_resolver;
 
 import 'dart:collection';
 
 import 'ast.dart';
 import 'element.dart';
@@ skipping 974 matching lines @@
     //
     if (node.isSynthetic) {
       return null;
     }
     //
     // Ignore nodes that should have been resolved before getting here.
     //
     if (node.inDeclarationContext()) {
       return null;
     }
+    if (node.staticElement is LocalVariableElement ||
+        node.staticElement is ParameterElement) {
+      return null;
+    }
     AstNode parent = node.parent;
     if (parent is FieldFormalParameter) {
       return null;
     } else if (parent is ConstructorFieldInitializer &&
         parent.fieldName == node) {
       return null;
     } else if (parent is Annotation && parent.constructorName == node) {
       return null;
     }
     //
@@ skipping 1575 matching lines @@
 
   @override
   Element get staticElement => null;
 
   @override
   accept(AstVisitor visitor) => null;
 
   @override
   void visitChildren(AstVisitor visitor) {}
 }