Overwrite the handler using Set.

src/list-inl.h

 // Copyright 2006-2009 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 86 matching lines @@
 
 template<typename T, class P>
 Vector<T> List<T, P>::AddBlock(T value, int count, P alloc) {
   int start = length_;
   for (int i = 0; i < count; i++) Add(value, alloc);
   return Vector<T>(&data_[start], count);
 }
 
 
 template<typename T, class P>
+void List<T, P>::Set(int index, const T& elm) {
+  ASSERT(index >= 0 && index <= length_);
+  data_[index] = elm;
+}
+
+
+template<typename T, class P>
 void List<T, P>::InsertAt(int index, const T& elm, P alloc) {
   ASSERT(index >= 0 && index <= length_);
   Add(elm, alloc);
   for (int i = length_ - 1; i > index; --i) {
     data_[i] = data_[i - 1];
   }
   data_[index] = elm;
 }
 
 
@@ skipping 149 matching lines @@
 
 template <typename T>
 int SortedListBSearch(const List<T>& list, T elem) {
   return SortedListBSearch<T, ElementCmp<T> > (list, ElementCmp<T>(elem));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LIST_INL_H_