Compute the correct signature for default constructors.

dart/sdk/lib/_internal/compiler/implementation/dart_backend/backend.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.
 
 part of dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 339 matching lines @@
         if (member.isConstructor()) continue NextClassElement;
       }
       if (classElement.constructors.isEmpty) continue NextClassElement;
 
       // TODO(antonm): check with AAR team if there is better approach.
       // As an idea: provide template as a Dart code---class C { C.name(); }---
       // and then overwrite necessary parts.
       var classNode = classElement.parseNode(compiler);
       SynthesizedConstructorElementX constructor =
           new SynthesizedConstructorElementX(
-              classElement.name, null, classElement);
+              classElement.name, null, classElement, false);
       constructor.type = new FunctionType(
           constructor,
           compiler.types.voidType,
           const Link<DartType>(),
           const Link<DartType>(),
           const Link<SourceString>(),
           const Link<DartType>()
           );
       constructor.cachedNode = new FunctionExpression(
           new Send(classNode.name, synthesizedIdentifier),
@@ skipping 175 matching lines @@
 }
 
 compareElements(e0, e1) {
   int result = compareBy((e) => e.getLibrary().canonicalUri.toString())(e0, e1);
   if (result != 0) return result;
   return compareBy((e) => e.position().charOffset)(e0, e1);
 }
 
 List<Element> sortElements(Iterable<Element> elements) =>
     sorted(elements, compareElements);