scsi_pkt(9S)

u_int		pkt_flags;			/* was type u_long */
int			pkt_time;			/* was type long */
ssize_t	pkt_resid;			/* was type long */
u_int		pkt_state;			/* was type u_long */
u_int		pkt_statistics;	/* was type u_long */

Since the flags, state and statistics fields do not need to grow they have been redefined as 32-bit integers. The data transfer size pkt_resid field does grow and has been redefined as ssize_t.