Implement constructor bodies and initializers in CPS->JS backend.

pkg/compiler/lib/src/js_backend/codegen/task.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.
 
 /// Generate code using the cps-based IR pipeline.
 library code_generator_task;
 
 import 'glue.dart';
 import 'codegen.dart';
 import 'unsugar.dart';
@@ skipping 78 matching lines @@
   }
 
   void traceGraph(String title, var irObject) {
     if (tracer != null) {
       tracer.traceGraph(title, irObject);
     }
   }
 
   cps.FunctionDefinition compileToCpsIR(AstElement element) {
     // TODO(sigurdm): Support these constructs.
-    if (element.isGenerativeConstructorBody ||
-        element.isNative ||
+    if (element.isNative ||
         element.isField) {
       giveUp('unsupported element kind: ${element.name}:${element.kind}');
     }
 
     cps.FunctionDefinition cpsNode = irBuilderTask.buildNode(element);
     if (cpsNode == null) {
       giveUp('unable to build cps definition of $element');
     }
     traceGraph("IR Builder", cpsNode);
     new UnsugarVisitor(glue).rewrite(cpsNode);
@@ skipping 115 matching lines @@
       endSourcePosition =
           new TokenSourceFileLocation(sourceFile, endToken, name);
     }
     return node.withPosition(sourcePosition, endSourcePosition);
   }
 
   SourceFile sourceFileOfElement(Element element) {
     return element.implementation.compilationUnit.script.file;
   }
 }