Remove PROHIBITS_OVERWRITING as it is subsumed by non-configurable properties.

src/objects-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 6375 matching lines @@
 bool AccessorInfo::all_can_write() {
   return BooleanBit::get(flag(), kAllCanWriteBit);
 }
 
 
 void AccessorInfo::set_all_can_write(bool value) {
   set_flag(BooleanBit::set(flag(), kAllCanWriteBit, value));
 }
 
 
-bool AccessorInfo::prohibits_overwriting() {
-  return BooleanBit::get(flag(), kProhibitsOverwritingBit);
-}
-
-
-void AccessorInfo::set_prohibits_overwriting(bool value) {
-  set_flag(BooleanBit::set(flag(), kProhibitsOverwritingBit, value));
-}
-
-
 PropertyAttributes AccessorInfo::property_attributes() {
   return AttributesField::decode(static_cast<uint32_t>(flag()->value()));
 }
 
 
 void AccessorInfo::set_property_attributes(PropertyAttributes attributes) {
   set_flag(Smi::FromInt(AttributesField::update(flag()->value(), attributes)));
 }
 
 
 bool AccessorInfo::IsCompatibleReceiver(Object* receiver) {
   Object* function_template = expected_receiver_type();
   if (!function_template->IsFunctionTemplateInfo()) return true;
   return FunctionTemplateInfo::cast(function_template)->IsTemplateFor(receiver);
 }
 
 
 void ExecutableAccessorInfo::clear_setter() {
   set_setter(GetIsolate()->heap()->undefined_value(), SKIP_WRITE_BARRIER);
 }
 
 
 void AccessorPair::set_access_flags(v8::AccessControl access_control) {
   int current = access_flags()->value();
   current = BooleanBit::set(current,
-                            kProhibitsOverwritingBit,
-                            access_control & PROHIBITS_OVERWRITING);
-  current = BooleanBit::set(current,
                             kAllCanReadBit,
                             access_control & ALL_CAN_READ);
   current = BooleanBit::set(current,
                             kAllCanWriteBit,
                             access_control & ALL_CAN_WRITE);
   set_access_flags(Smi::FromInt(current));
 }
 
 
 bool AccessorPair::all_can_read() {
   return BooleanBit::get(access_flags(), kAllCanReadBit);
 }
 
 
 bool AccessorPair::all_can_write() {
   return BooleanBit::get(access_flags(), kAllCanWriteBit);
 }
 
 
-bool AccessorPair::prohibits_overwriting() {
-  return BooleanBit::get(access_flags(), kProhibitsOverwritingBit);
-}
-
-
 template<typename Derived, typename Shape, typename Key>
 void Dictionary<Derived, Shape, Key>::SetEntry(int entry,
                                                Handle<Object> key,
                                                Handle<Object> value) {
   SetEntry(entry, key, value, PropertyDetails(Smi::FromInt(0)));
 }
 
 
 template<typename Derived, typename Shape, typename Key>
 void Dictionary<Derived, Shape, Key>::SetEntry(int entry,
@@ skipping 401 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_