MFC r297935:

MFC r297935:

  Separate POSIX sem/shm objects in jails, by prepending the jail's path
  name to the object's "path".  While the objects don't have real path
  names, it's a filesystem-like namespace, which allows jails to be
  kept to their own space, but still allows the system / jail parent to
  access a jail's IPC.

MFC r297936:

  Separate POSIX mqueue objects in jails; actually, separate them by the
  jail's root, so jails that don't have their own filesystem directory
  also won't have their own mqueue namespace.

MFC r297976:

  Clean up some style(9) violations.

MFC r298567:

   Use the new PR_METHOD_REMOVE to clean up jail handling in POSIX
   message queues.

PR:		208082
Submitted by:	delphij

git-svn-id: svn://svn.freebsd.org/base/stable/10@325783 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f