[strong] Implement per-object restrictions behaviour of delete operator

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 <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 3600 matching lines @@
     return PropertyDetails(
         Smi::cast(this->get(DerivedHashTable::EntryToIndex(entry) + 2)));
   }
 
   // Set the details for entry.
   void DetailsAtPut(int entry, PropertyDetails value) {
     this->set(DerivedHashTable::EntryToIndex(entry) + 2, value.AsSmi());
   }
 
   // Delete a property from the dictionary.
-  static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry);
+  static Handle<Object> DeleteProperty(Handle<Derived> dictionary, int entry,
+                                       bool strong_obj = false);
 
   // Attempt to shrink the dictionary after deletion of key.
   MUST_USE_RESULT static inline Handle<Derived> Shrink(
       Handle<Derived> dictionary,
       Key key) {
     return DerivedHashTable::Shrink(dictionary, key);
   }
 
   // Sorting support
   // TODO(dcarney): templatize or move to SeededNumberDictionary
@@ skipping 7498 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_