Revert of [heap] Remove size specializations in static object visitors.

src/objects-body-descriptors-inl.h

Index: src/objects-body-descriptors-inl.h
diff --git a/src/objects-body-descriptors-inl.h b/src/objects-body-descriptors-inl.h
index ff679c984629063c6e1554ec680ad6d5848601f6..d34c0f04e40a9e68bce0b75011441de7a7761209 100644
--- a/src/objects-body-descriptors-inl.h
+++ b/src/objects-body-descriptors-inl.h
@@ -124,31 +124,6 @@
   static inline void IterateBody(HeapObject* obj, int object_size) {
     Heap* heap = obj->GetHeap();
     IterateBodyImpl<StaticVisitor>(heap, obj, kStartOffset, object_size);
-  }
-
-  static inline int SizeOf(Map* map, HeapObject* object) {
-    return map->instance_size();
-  }
-};
-
-class JSObject::FastBodyDescriptor final : public BodyDescriptorBase {
- public:
-  static const int kStartOffset = JSReceiver::kPropertiesOffset;
-
-  static bool IsValidSlot(HeapObject* obj, int offset) {
-    return offset >= kStartOffset;
-  }
-
-  template <typename ObjectVisitor>
-  static inline void IterateBody(HeapObject* obj, int object_size,
-                                 ObjectVisitor* v) {
-    IteratePointers(obj, kStartOffset, object_size, v);
-  }
-
-  template <typename StaticVisitor>
-  static inline void IterateBody(HeapObject* obj, int object_size) {
-    Heap* heap = obj->GetHeap();
-    IteratePointers<StaticVisitor>(heap, obj, kStartOffset, object_size);
   }
 
   static inline int SizeOf(Map* map, HeapObject* object) {