dart2js cps: Fix default values for forwarding constructors.

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart

 // Copyright (c) 2013, 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.ir_builder_task;
 
 import '../closure.dart' as closurelib;
 import '../closure.dart' hide ClosureScope;
 import '../constants/expressions.dart';
 import '../dart_types.dart';
@@ skipping 3619 matching lines @@
   @override
   ir.Primitive handleConstructorInvoke(
       ast.NewExpression node,
       ConstructorElement constructor,
       DartType type,
       ast.NodeList arguments,
       CallStructure callStructure,
       _) {
     List<ir.Primitive> arguments =
         node.send.arguments.mapToList(visit, growable:false);
-    arguments = normalizeStaticArguments(
-        callStructure, constructor, arguments);
+    // Use default values from the effective target, not the immediate target.
+    ConstructorElement target = constructor.effectiveTarget;
+    arguments = normalizeStaticArguments(callStructure, target, arguments);
     return irBuilder.buildConstructorInvocation(
-        constructor.effectiveTarget,
+        target,
         callStructure,
         constructor.computeEffectiveTargetType(type),
         arguments);
   }
 
   @override
   ir.Primitive buildStaticNoSuchMethod(Selector selector,
                                        List<ir.Primitive> arguments) {
     Element thrower = backend.getThrowNoSuchMethod();
     ir.Primitive receiver = irBuilder.buildStringConstant('');
@@ skipping 113 matching lines @@
     node.body = replacementFor(node.body);
   }
 }
 
 /// Visit a just-deleted subterm and unlink all [Reference]s in it.
 class RemovalVisitor extends ir.RecursiveVisitor {
   processReference(ir.Reference reference) {
     reference.unlink();
   }
 }