Make incremental marking clear type feedback cells.

src/incremental-marking.cc

Index: src/incremental-marking.cc
diff --git a/src/incremental-marking.cc b/src/incremental-marking.cc
index ebbee25ac02d749551ea1c1de200db32987bd276..e3040eea6b712cda81a26f60b3a12ca4a47dd048 100644
--- a/src/incremental-marking.cc
+++ b/src/incremental-marking.cc
@@ -196,12 +196,6 @@ class IncrementalMarkingMarkingVisitor
     MarkObject(heap, target);
   }
 
-  static void VisitCode(Map* map, HeapObject* object) {
-    Heap* heap = map->GetHeap();
-    Code* code = reinterpret_cast<Code*>(object);
-    code->CodeIterateBody<IncrementalMarkingMarkingVisitor>(heap);
-  }
-
   static void VisitJSWeakMap(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
     VisitPointers(heap,