rem: preloaded_symbols = 0;
add: preloaded_symbols = NULL;
context: presym_free_symlists (){  lt_dlsymlists_t *lists;  LT_DLMUTEX_LOCK ();  lists = preloaded_symbols;  while (lists)    {      lt_dlsymlists_t	*tmp = lists;      lists = lists->next;      LT_DLFREE (tmp);    }  preloaded_symbols = 0;  LT_DLMUTEX_UNLOCK ();  return 0;}