correctly invalidate global cells

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 6ce23da02908f33323bd8ce6a7b6b1ee4c7e319f..fa621753fdcaef7381373ee2839d2def7f902120 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1612,8 +1612,6 @@ void Heap::Scavenge() {
       PropertyCell* cell = PropertyCell::cast(heap_object);
       Address value_address = cell->ValueAddress();
       scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(value_address));
-      Address type_address = cell->TypeAddress();
-      scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(type_address));
     }
   }
 
@@ -2894,7 +2892,6 @@ AllocationResult Heap::AllocatePropertyCell() {
   cell->set_dependent_code(DependentCode::cast(empty_fixed_array()),
                            SKIP_WRITE_BARRIER);
   cell->set_value(the_hole_value());
-  cell->set_type(HeapType::None());
   return result;
 }