[Arguments] Support deletion of arguments properties.

src/objects.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1853 matching lines @@
   MaybeObject* GetElementPostInterceptor(Object* receiver, uint32_t index);
 
   MUST_USE_RESULT MaybeObject* DeletePropertyPostInterceptor(String* name,
                                                              DeleteMode mode);
   MUST_USE_RESULT MaybeObject* DeletePropertyWithInterceptor(String* name);
 
   MUST_USE_RESULT MaybeObject* DeleteElementPostInterceptor(uint32_t index,
                                                             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);
+
   PropertyAttributes GetPropertyAttributePostInterceptor(JSObject* receiver,
                                                          String* name,
                                                          bool continue_search);
   PropertyAttributes GetPropertyAttributeWithInterceptor(JSObject* receiver,
                                                          String* name,
                                                          bool continue_search);
   PropertyAttributes GetPropertyAttributeWithFailedAccessCheck(
       Object* receiver,
       LookupResult* result,
       String* name,
@@ skipping 4761 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_