Added ability to remove prototype from function. In this case, [[Construct]] ...

src/objects.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4888 matching lines @@
     // needed.  At that point, a new initial map is created and the
     // prototype is put into the initial map where it belongs.
     set_prototype_or_initial_map(value);
   }
   return value;
 }
 
 
 
 Object* JSFunction::SetPrototype(Object* value) {
+  ASSERT(should_have_prototype());
   Object* construct_prototype = value;
 
   // If the value is not a JSObject, store the value in the map's
   // constructor field so it can be accessed.  Also, set the prototype
   // used for constructing objects to the original object prototype.
   // See ECMA-262 13.2.2.
   if (!value->IsJSObject()) {
     // Copy the map so this does not affect unrelated functions.
     // Remove map transitions because they point to maps with a
     // different prototype.
     Object* new_map = map()->CopyDropTransitions();
     if (new_map->IsFailure()) return new_map;
     set_map(Map::cast(new_map));
     map()->set_constructor(value);
     map()->set_non_instance_prototype(true);
     construct_prototype =
         Top::context()->global_context()->initial_object_prototype();
   } else {
     map()->set_non_instance_prototype(false);
   }
 
   return SetInstancePrototype(construct_prototype);
 }
 
 
+Object* JSFunction::RemovePrototype() {
+  ASSERT(map() == context()->global_context()->function_map());
+  set_map(context()->global_context()->function_without_prototype_map());
+  set_prototype_or_initial_map(Heap::the_hole_value());
+  return this;
+}
+
+
 Object* JSFunction::SetInstanceClassName(String* name) {
   shared()->set_instance_class_name(name);
   return this;
 }
 
 
 Context* JSFunction::GlobalContextFromLiterals(FixedArray* literals) {
   return Context::cast(literals->get(JSFunction::kLiteralGlobalContextIndex));
 }
 
@@ skipping 3592 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif
 
 
 } }  // namespace v8::internal