Further cleanups to annotation elements now that #25706 is fixed.

pkg/analyzer/lib/src/dart/constant/utilities.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.constant.utilities;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 28 matching lines @@
   ConstantAstCloner() : super(true);
 
   @override
   ConstructorName visitConstructorName(ConstructorName node) {
     ConstructorName name = super.visitConstructorName(node);
     name.staticElement = node.staticElement;
     return name;
   }
 
   @override
+  Annotation visitAnnotation(Annotation node) {
+    Annotation annotation = super.visitAnnotation(node);
+    annotation.element = node.element;
+    return annotation;
+  }
+
+  @override
   FunctionExpression visitFunctionExpression(FunctionExpression node) {
     FunctionExpression expression = super.visitFunctionExpression(node);
     expression.element = node.element;
     return expression;
   }
 
   @override
   InstanceCreationExpression visitInstanceCreationExpression(
       InstanceCreationExpression node) {
     InstanceCreationExpression expression =
@@ skipping 245 matching lines @@
   @override
   Object visitSuperConstructorInvocation(SuperConstructorInvocation node) {
     super.visitSuperConstructorInvocation(node);
     ConstructorElement constructor = getConstructorImpl(node.staticElement);
     if (constructor != null) {
       _callback(constructor);
     }
     return null;
   }
 }