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

src/accessors.cc

 // 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.
 
 #include "v8.h"
 #include "accessors.h"
 
 #include "compiler.h"
 #include "contexts.h"
 #include "deoptimizer.h"
@@ skipping 23 matching lines @@
     Isolate* isolate,
     Handle<String> name,
     AccessorGetterCallback getter,
     AccessorSetterCallback setter,
     PropertyAttributes attributes) {
   Factory* factory = isolate->factory();
   Handle<ExecutableAccessorInfo> info = factory->NewExecutableAccessorInfo();
   info->set_property_attributes(attributes);
   info->set_all_can_read(false);
   info->set_all_can_write(false);
-  info->set_prohibits_overwriting(false);
   info->set_name(*name);
   Handle<Object> get = v8::FromCData(isolate, getter);
   Handle<Object> set = v8::FromCData(isolate, setter);
   info->set_getter(*get);
   info->set_setter(*set);
   return info;
 }
 
 
 Handle<ExecutableAccessorInfo> Accessors::CloneAccessor(
@@ skipping 1298 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal