Use null instead of undefined for deleted elements in code caches....

src/objects-inl.h

 // Copyright 2006-2008 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 959 matching lines @@
 
 
 void FixedArray::set_undefined(int index) {
   ASSERT(index >= 0 && index < this->length());
   ASSERT(!Heap::InNewSpace(Heap::undefined_value()));
   WRITE_FIELD(this, kHeaderSize + index * kPointerSize,
               Heap::undefined_value());
 }
 
 
+void FixedArray::set_null(int index) {
+  ASSERT(index >= 0 && index < this->length());
+  ASSERT(!Heap::InNewSpace(Heap::null_value()));
+  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, Heap::null_value());
+}
+
+
 void FixedArray::set_the_hole(int index) {
   ASSERT(index >= 0 && index < this->length());
   ASSERT(!Heap::InNewSpace(Heap::the_hole_value()));
   WRITE_FIELD(this, kHeaderSize + index * kPointerSize, Heap::the_hole_value());
 }
 
 
 bool DescriptorArray::IsEmpty() {
   ASSERT(this == Heap::empty_descriptor_array() ||
          this->length() > 2);
@@ skipping 1135 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_