Give each function prototype a fresh copy of the object function map.

This avoid unwanted sharing between different function prototypes and in
general should help inlining because constant function properties on one
prototype don't affect other prototypes anymore.

BUG=v8:1716
Review URL: http://codereview.chromium.org/7994001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9393 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -3265,8 +3265,18 @@ MaybeObject* Heap::AllocateFunctionPrototype(JSFunction* function) {
   // different context.
   JSFunction* object_function =
       function->context()->global_context()->object_function();
+
+  // Each function prototype gets a copy of the object function map.
+  // This avoid unwanted sharing of maps between prototypes of different
+  // constructors.
+  Map* new_map;
+  ASSERT(object_function->has_initial_map());
+  { MaybeObject* maybe_map =
+        object_function->initial_map()->CopyDropTransitions();
+    if (!maybe_map->To<Map>(&new_map)) return maybe_map;
+  }
   Object* prototype;
-  { MaybeObject* maybe_prototype = AllocateJSObject(object_function);
+  { MaybeObject* maybe_prototype = AllocateJSObjectFromMap(new_map);
     if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype;
   }
   // When creating the prototype for the function we must set its

src/objects.cc

@@ -1070,7 +1070,6 @@ void JSObject::JSObjectShortPrint(StringStream* accumulator) {
 
 
 void HeapObject::HeapObjectShortPrint(StringStream* accumulator) {
-  // if (!HEAP->InNewSpace(this)) PrintF("*", this);
   Heap* heap = GetHeap();
   if (!heap->Contains(this)) {
     accumulator->Add("!!!INVALID POINTER!!!");