Integrate capabilities 8 branch from stable/8.
Manually merge r197624 from head to capabilities8:

  Add audit events for process descriptor system calls, which will appear in
  a future OpenBSM release.

  Sponsored by:   Google
  Obtained from:  TrustedBSD Project
Manually merge r197720 from head to capabilities8:

  Don't comment on stream socket handling in sosend_dgram, since that's
  not handled.
Manually merge r197775 from head to capabilities8:

  First cut at implementing SOCK_SEQPACKET support for UNIX (local) domain
  sockets.  This allows for reliable bi-directional datagram communication
  over UNIX domain sockets, in contrast to SOCK_DGRAM (M:N, unreliable) or
  SOCK_STERAM (bi-directional bytestream).  Largely, this reuses existing
  UNIX domain socket code.  This allows applications requiring record-
  oriented semantics to do so reliably via local IPC.

  Some implementation notes (also present in XXX comments):

  - Currently we lack an sbappend variant able to do datagrams and control
    data without doing addresses, so we mark SOCK_SEQPACKET as PR_ADDR.
    Adding a new variant will solve this problem.

  - UNIX domain sockets on FreeBSD provide back-pressure/flow control
    notification for stream sockets by manipulating the send socket
    buffer's size during pru_send and pru_rcvd.  This trick works less well
    for SOCK_SEQPACKET as sosend_generic() uses sb_hiwat not just to
    manage blocking, but also to determine maximum datagram size.  Fixing
    this requires rethinking how back-pressure is done for SOCK_SEQPACKET;
    in the mean time, it's possible to get EMSGSIZE when buffers fill,
    instead of blocking.

  Discussed with: benl
  Reviewed by:    bz, rpaulo
  Sponsored by:   Google
Manually merge r197777 from head to capabilities8:

  netstat(1) support for UNIX SOCK_SEQPACKET sockets -- changes were required
  only for the kvm case, as we supported SOCK_SEQPACKET via sysctl already.

  Sponsored by:   Google
Manually merge r197778 from head to capabilities8:

  SOCK_SEQPACKET is now supported on UNIX domain sockets.

  Sponsored by:   Google
Manually merge r197779 from head to capabilities8:

  Bump unix(4) man page date for SOCK_SEQPACKET.

  Suggested by:   bz
Manually merge r197794 from head to capabilities8:

  Fix build on amd64, where sysctl arg1 is a pointer.

  Reported by:    Mr Tinderbox
Manually merge r197804 from head to capabilities8:

  Add basename_r(3) to complement basename(3).  basename_r(3) which accepts
  a caller-allocated buffer of at least MAXPATHLEN, rather than using a
  global buffer.

  Sponsored by:   Google
Manually merge r197808 from head to capabilities8:

  In rtld's map_object(), use pread(..., 0) rather than read() to read the
  ELF header from the front of the file.  As all other I/O on the binary
  is done using mmap(), this avoids the need for seek privileges on the
  file descriptor during run-time linking.

  Sponsored by:   Google
Merge TrustedBSD capabilities prototype snapshot from Perforce to
capabilities8 project branch; primary development will continue in
Perforce, but this branch will allow 8.x users to work with the
capabilities parts without braving 9.x.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Sample capabilities kernel configuration.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Merge P4 c169338 to capabilities8:

  Correct two spelling nits.

  Submitted by:    ceri
Merge previously omitted gzip.h from Perforce to capabilities8.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Merge Perforce c169466 into the capabilities8 branch:

  printf() size_t's using %zu to please 64-bit builds.
Merge c169468 from Perforce to capabilities8 branch:

	Declare new cap/procdesc system calls NOPROTO in the compat32
	syscall table.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Regenerate.
Merge Perforce c169482 to capabilities8 branch:

  Add missing capability.h include for amd64 build.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Merge Perforce c169487 to capabilities8 branch:

  Add missing capability argument to fget(9) for 32-bit FreeBSD
  compatibility code.

Obtained from:	TrustedBSD Project
Sponsored by:	Google
Merge Perforce c169494 to capabilities8 branch:

  Align 64-bit capability field at a 64-bit offset in struct
  kinfo_file, otherwise the compiler will introduce additional
  padding, changing the size of the overall structure.

  Spotted by:     Jonathan Anderson