Count statistics for the specific address family.

MFC after:	1 week
Sponsored by:	Yandex LLC
Bump FreeBSD_version for r274462 - add ppoll() system call.
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced