Set 'enclosingElement' for FunctionElementImpl_forLUB.

pkg/analyzer/lib/src/dart/element/element.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.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 4525 matching lines @@
 
   @override
   bool get isSynthetic => true;
 }
 
 /**
  * Implementation of [FunctionElementImpl] for a synthetic function element
  * that was synthesized by a LUB computation.
  */
 class FunctionElementImpl_forLUB extends FunctionElementImpl {
-  @override
-  final CompilationUnitElementImpl enclosingUnit;
-
-  @override
-  final TypeParameterizedElementMixin enclosingTypeParameterContext;
-
   final EntityRef _entityRef;
 
-  FunctionElementImpl_forLUB(
-      this.enclosingUnit, this.enclosingTypeParameterContext, this._entityRef)
-      : super('', -1);
+  FunctionElementImpl_forLUB(ElementImpl enclosingElement, this._entityRef)
+      : super.forSerialized(null, enclosingElement);
 
   @override
   bool get isSynthetic => true;
 
   @override
   List<ParameterElement> get parameters {
     return _parameters ??= ParameterElementImpl
         .resynthesizeList(_entityRef.syntheticParams, this, synthetic: true);
   }
 
@@ skipping 4532 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }