Handle use of constant constructors with default values.

pkg/compiler/lib/src/closure.dart

 // Copyright (c) 2012, 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 closureToClassMapper;
 
 import 'common.dart';
 import 'common/names.dart' show Identifiers;
 import 'common/resolution.dart' show ParsingContext, Resolution;
 import 'common/tasks.dart' show CompilerTask;
@@ skipping 153 matching lines @@
   accept(ElementVisitor visitor, arg) {
     return visitor.visitClosureFieldElement(this, arg);
   }
 
   Element get analyzableElement => closureClass.methodElement.analyzableElement;
 
   @override
   List<FunctionElement> get nestedClosures => const <FunctionElement>[];
 
   @override
+  bool get hasConstant => false;
+
+  @override
   ConstantExpression get constant => null;
 }
 
 // TODO(ahe): These classes continuously cause problems.  We need to find
 // a more general solution.
 class ClosureClassElement extends ClassElementX {
   DartType rawType;
   DartType thisType;
   FunctionType callType;
 
@@ skipping 119 matching lines @@
   Node get node {
     throw new UnsupportedError("BoxFieldElement.node");
   }
 
   @override
   ResolvedAst get resolvedAst {
     throw new UnsupportedError("BoxFieldElement.resolvedAst");
   }
 
   @override
+  bool get hasConstant => false;
+
+  @override
   ConstantExpression get constant => null;
 }
 
 /// A local variable used encode the direct (uncaptured) references to [this].
 class ThisLocal extends Local {
   final ExecutableElement executableContext;
   final hashCode = ++ElementX.elementHashCode;
 
   ThisLocal(this.executableContext);
 
@@ skipping 856 matching lines @@
 ///
 /// Move the below classes to a JS model eventually.
 ///
 abstract class JSEntity implements Entity {
   Entity get declaredEntity;
 }
 
 abstract class PrivatelyNamedJSEntity implements JSEntity {
   Entity get rootOfScope;
 }