[heap] Reland "Remove size specializations in static object visitors. (patchset #4 id:60001 of http…

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 920cb0772b3c124602c0f21870ba6ecdd5c4cd0a..3f54f6f690cdb85f929d586563ec24ffd9130ee9 100644
--- a/src/objects-body-descriptors-inl.h
+++ b/src/objects-body-descriptors-inl.h
@@ -131,6 +131,31 @@ class JSObject::BodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
+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) {
+    return map->instance_size();
+  }
+};
+
 // Iterates the function object according to the visiting policy.
 template <JSFunction::BodyVisitingPolicy body_visiting_policy>
 class JSFunction::BodyDescriptorImpl final : public BodyDescriptorBase {