rem: append_repeated_char (struct Spec_list *list, unsigned int the_char, size_t repeat_count)
add: append_repeated_char (struct Spec_list *list, unsigned char the_char, count repeat_count)
context: append_repeated_char (struct Spec_list *list, unsigned int the_char,		      size_t repeat_count){  struct List_element *new;  new = (struct List_element *) xmalloc (sizeof (struct List_element));  new->next = NULL;  new->type = RE_REPEATED_CHAR;  new->u.repeated_char.the_repeated_char = the_char;  new->u.repeated_char.repeat_count = repeat_count;  assert (list->tail);  list->tail->next = new;  list->tail = new;}