Use Entity instead of Element in ConstantValue

pkg/compiler/lib/src/constants/expressions.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 dart2js.constants.expressions;
 
 import '../common.dart';
 import '../constants/constant_system.dart';
 import '../core_types.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart'
     show
         ConstructorElement,
         FieldElement,
-        FunctionElement,
+        MethodElement,
         PrefixElement,
         VariableElement;
 import '../resolution/operators.dart';
 import '../tree/dartstring.dart' show DartString;
 import '../universe/call_structure.dart' show CallStructure;
 import 'evaluation.dart';
 import 'values.dart';
 
 enum ConstantExpressionKind {
   BINARY,
@@ skipping 780 matching lines @@
   int _computeHashCode() => 13 * element.hashCode;
 
   @override
   bool _equals(VariableConstantExpression other) {
     return element == other.element;
   }
 }
 
 /// Reference to a top-level or static function.
 class FunctionConstantExpression extends ConstantExpression {
-  final FunctionElement element;
+  final MethodElement element;
 
   FunctionConstantExpression(this.element);
 
   ConstantExpressionKind get kind => ConstantExpressionKind.FUNCTION;
 
   accept(ConstantExpressionVisitor visitor, [context]) {
     return visitor.visitFunction(this, context);
   }
 
   @override
   void _createStructuredText(StringBuffer sb) {
     sb.write('Function(element=$element)');
   }
 
   @override
   ConstantValue evaluate(
       Environment environment, ConstantSystem constantSystem) {
-    return new FunctionConstantValue(element);
+    return new FunctionConstantValue(element, element.type);
   }
 
   @override
   int _computeHashCode() => 13 * element.hashCode;
 
   @override
   bool _equals(FunctionConstantExpression other) {
     return element == other.element;
   }
 
@@ skipping 1043 matching lines @@
     visit(exp.name);
     if (exp.defaultValue != null) {
       sb.write(', defaultValue: ');
       visit(exp.defaultValue);
     }
     sb.write(')');
   }
 
   String toString() => sb.toString();
 }