Add an insert function to our list utility class.

src/list-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 41 matching lines @@
 template<typename T, class P>
 Vector<T> List<T, P>::AddBlock(const T& element, int count) {
   int start = length_;
   for (int i = 0; i < count; i++)
     Add(element);
   return Vector<T>(&data_[start], count);
 }
 
 
 template<typename T, class P>
+T& List<T, P>::Insert(int i, const T& element) {
+  int free_index = length_ - 1;
+  Add(last());  // Add grows the list if necessary.
+  while (free_index > i) {
+    data_[free_index] = data_[free_index - 1];
+    free_index--;
+  }
+  data_[free_index] = element;
+}
+
+
+template<typename T, class P>
 T List<T, P>::Remove(int i) {
   T element = at(i);
   length_--;
   while (i < length_) {
     data_[i] = data_[i + 1];
     i++;
   }
   return element;
 }
 
@@ skipping 48 matching lines @@
   ASSERT(capacity >= 0);
   data_ = (capacity > 0) ? NewData(capacity) : NULL;
   capacity_ = capacity;
   length_ = 0;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LIST_INL_H_