FreeBSD: handle V_PCATCH
See https://cgit.FreeBSD.org/src/commit/?id=a75d1ddd74312f5dd79bc1e965f7077679659f2e
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #13910