Similar to 233760 and 236717, export some more useful info about the
kernel-based POSIX semaphore descriptors to userland via procstat(1) and
fstat(1):
- Change sem file descriptors to track the pathname they are associated
  with and add a ksem_info() method to copy the path out to a
  caller-supplied buffer.
- Use the fo_stat() method of shared memory objects and ksem_info() to
  export the path, mode, and value of a semaphore via struct kinfo_file.
- Add a struct semstat to the libprocstat(3) interface along with a
  procstat_get_sem_info() to export the mode and value of a semaphore.
- Teach fstat about semaphores and to display their path, mode, and value.

	fuser(1) requires a filename.

Approved by:	cperciva (mentor, implicit)

	Remove trailing whitespace per mdoc lint warning

Approved by:	cperciva (implicit)

Export some more useful info about shared memory objects to userland
via procstat(1) and fstat(1):
- Change shm file descriptors to track the pathname they are associated
  with and add a shm_path() method to copy the path out to a caller-supplied
  buffer.
- Use the fo_stat() method of shared memory objects and shm_path() to
  export the path, mode, and size of a shared memory object via
  struct kinfo_file.
- Add a struct shmstat to the libprocstat(3) interface along with a
  procstat_get_shm_info() to export the mode and size of a shared memory
  object.
- Change procstat to always print out the path for a given object if it
  is valid.
- Teach fstat about shared memory objects and to display their path,
  mode, and size.

several filesystem layers mounted at the specified path.

Pointy hat to:	pluknet
Reported by:	flo via broken tinderbox

 Print the owner process for unix domain sockets when restricted to the
 specified files.

PR:		bin/143962

The code did  !strncasecmp(str, "sig", 4)  which is not useful.

Also change "sig" to "SIG" matching the uppercase signal names as of
r218285. This has little effect because fuser does not enable locale.

- fuser(1) writes usernames to stderr, not stdout [1]
- Add history section.

Submitted by: Pieter de Goeje <pieter@degoeje.nl> [1]

Submitted by:	avg@