Generators return boxed values

src/full-codegen.h

Index: src/full-codegen.h
diff --git a/src/full-codegen.h b/src/full-codegen.h
index 3734ae52678c950e8a1a6aa88c869de4aa58247a..32242b297b430a48f904073f71edf61a5577c780 100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -410,6 +410,11 @@ class FullCodeGenerator: public AstVisitor {
   // this has to be a separate pass _before_ populating or executing any module.
   void AllocateModules(ZoneList<Declaration*>* declarations);
 
+  // Generator code to return a fresh iterator result object.  The "value"
+  // property is set to a value popped from the stack, and "done" is set
+  // according to the argument.
+  void EmitReturnIteratorResult(bool done);
+
   // Try to perform a comparison as a fast inlined literal compare if
   // the operands allow it.  Returns true if the compare operations
   // has been matched and all code generated; false otherwise.