bsd-user: Implement procctl(2) along with necessary conversion functions.

Implement t2h_procctl_cmd, h2t_reaper_status, h2t_reaper_pidinfo and h2t/t2h reaper_kill conversion functions.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20230925182425.3163-22-kariem.taha2.7@gmail.com>
2 files changed