Migrate %TypedArray%.prototype.fill to C++

src/elements.h

Index: src/elements.h
diff --git a/src/elements.h b/src/elements.h
index d693092bfbea2ac3de3ed048a7d2e2a4d4cad25d..89ac5a250accc489f5b90ff96d3b691e2f7bd0ee 100644
--- a/src/elements.h
+++ b/src/elements.h
@@ -158,6 +158,10 @@ class ElementsAccessor {
   virtual uint32_t GetCapacity(JSObject* holder,
                                FixedArrayBase* backing_store) = 0;
 
+  virtual Object* Fill(Isolate* isolate, Handle<JSObject> receiver,
+                       Handle<Object> obj_value, uint32_t start,
+                       uint32_t end) = 0;
+
   // Check an Object's own elements for an element (using SameValueZero
   // semantics)
   virtual Maybe<bool> IncludesValue(Isolate* isolate, Handle<JSObject> receiver,