[Arguments] Support HasElement and ReferencesObject for arguments objects.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index d3083ccf3501c9d1933c099db3b1f077cbf1e10d..acd06402bb363d4bb34fa3bc1ce4357e26943235 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1871,12 +1871,17 @@ class JSObject: public HeapObject {
                                                             DeleteMode mode);
   MUST_USE_RESULT MaybeObject* DeleteElementWithInterceptor(uint32_t index);
 
-  // Deletion utilities taking an explicit backing store argument.
-  void DeleteFromFastElements(FixedArray* elements, uint32_t index);
-  MUST_USE_RESULT MaybeObject* DeleteFromDictionaryElements(
-      NumberDictionary* elements,
-      uint32_t index,
-      DeleteMode mode);
+  // Utilities taking an explicit backing store arguments.
+  MUST_USE_RESULT MaybeObject* DeleteFromElements(FixedArray* elements,
+                                                  ElementsKind kind,
+                                                  uint32_t index,
+                                                  DeleteMode mode);
+  bool ReferencesObjectFromElements(FixedArray* elements,
+                                    ElementsKind kind,
+                                    Object* object);
+  bool HasElementInElements(FixedArray* elements,
+                            ElementsKind kind,
+                            uint32_t index);
 
   PropertyAttributes GetPropertyAttributePostInterceptor(JSObject* receiver,
                                                          String* name,