marshal.c:410
static void
w_ivar(tbl, arg)
    st_table *tbl;
    struct dump_call_arg *arg;
{
    if (tbl) {
	w_long(tbl->num_entries, arg->arg);
	st_foreach(tbl, w_obj_each, (st_data_t)arg);
    }
    else {
	w_long(0, arg->arg);
    }
}
