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

src/objects.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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include "allocation.h"
 #include "assert-scope.h"
 #include "builtins.h"
@@ skipping 2423 matching lines @@
   inline int GetInternalFieldOffset(int index);
   inline Object* GetInternalField(int index);
   inline void SetInternalField(int index, Object* value);
   inline void SetInternalField(int index, Smi* value);
 
   // The following lookup functions skip interceptors.
   void LookupOwnRealNamedProperty(Handle<Name> name, LookupResult* result);
   void LookupRealNamedProperty(Handle<Name> name, LookupResult* result);
   void LookupRealNamedPropertyInPrototypes(Handle<Name> name,
                                            LookupResult* result);
-  void LookupCallbackProperty(Handle<Name> name, LookupResult* result);
 
   // Returns the number of properties on this object filtering out properties
   // with the specified attributes (ignoring interceptors).
   int NumberOfOwnProperties(PropertyAttributes filter = NONE);
   // Fill in details for properties into storage starting at the specified
   // index.
   void GetOwnPropertyNames(
       FixedArray* storage, int index, PropertyAttributes filter = NONE);
 
   // Returns the number of properties on this object filtering out properties
@@ skipping 7911 matching lines @@
   DECL_ACCESSORS(name, Object)
   DECL_ACCESSORS(flag, Smi)
   DECL_ACCESSORS(expected_receiver_type, Object)
 
   inline bool all_can_read();
   inline void set_all_can_read(bool value);
 
   inline bool all_can_write();
   inline void set_all_can_write(bool value);
 
-  inline bool prohibits_overwriting();
-  inline void set_prohibits_overwriting(bool value);
-
   inline PropertyAttributes property_attributes();
   inline void set_property_attributes(PropertyAttributes attributes);
 
   // Checks whether the given receiver is compatible with this accessor.
   inline bool IsCompatibleReceiver(Object* receiver);
 
   static inline AccessorInfo* cast(Object* obj);
 
   // Dispatched behavior.
   DECLARE_VERIFIER(AccessorInfo)
 
   // Append all descriptors to the array that are not already there.
   // Return number added.
   static int AppendUnique(Handle<Object> descriptors,
                           Handle<FixedArray> array,
                           int valid_descriptors);
 
   static const int kNameOffset = HeapObject::kHeaderSize;
   static const int kFlagOffset = kNameOffset + kPointerSize;
   static const int kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
   static const int kSize = kExpectedReceiverTypeOffset + kPointerSize;
 
  private:
   // Bit positions in flag.
   static const int kAllCanReadBit = 0;
   static const int kAllCanWriteBit = 1;
-  static const int kProhibitsOverwritingBit = 2;
-  class AttributesField: public BitField<PropertyAttributes, 3, 3> {};
+  class AttributesField: public BitField<PropertyAttributes, 2, 3> {};
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo);
 };
 
 
 enum AccessorDescriptorType {
   kDescriptorBitmaskCompare,
   kDescriptorPointerCompare,
   kDescriptorPrimitiveValue,
   kDescriptorObjectDereference,
@@ skipping 144 matching lines @@
 // failure.
 class AccessorPair: public Struct {
  public:
   DECL_ACCESSORS(getter, Object)
   DECL_ACCESSORS(setter, Object)
   DECL_ACCESSORS(access_flags, Smi)
 
   inline void set_access_flags(v8::AccessControl access_control);
   inline bool all_can_read();
   inline bool all_can_write();
-  inline bool prohibits_overwriting();
 
   static inline AccessorPair* cast(Object* obj);
 
   static Handle<AccessorPair> Copy(Handle<AccessorPair> pair);
 
   Object* get(AccessorComponent component) {
     return component == ACCESSOR_GETTER ? getter() : setter();
   }
 
   void set(AccessorComponent component, Object* value) {
@@ skipping 22 matching lines @@
   DECLARE_VERIFIER(AccessorPair)
 
   static const int kGetterOffset = HeapObject::kHeaderSize;
   static const int kSetterOffset = kGetterOffset + kPointerSize;
   static const int kAccessFlagsOffset = kSetterOffset + kPointerSize;
   static const int kSize = kAccessFlagsOffset + kPointerSize;
 
  private:
   static const int kAllCanReadBit = 0;
   static const int kAllCanWriteBit = 1;
-  static const int kProhibitsOverwritingBit = 2;
 
   // Strangely enough, in addition to functions and harmony proxies, the spec
   // requires us to consider undefined as a kind of accessor, too:
   //    var obj = {};
   //    Object.defineProperty(obj, "foo", {get: undefined});
   //    assertTrue("foo" in obj);
   bool IsJSAccessor(Object* obj) {
     return obj->IsSpecFunction() || obj->IsUndefined();
   }
 
@@ skipping 449 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_