MFC r289441:

Integrate tools/test/posixshm and tools/regression/posixshm into the FreeBSD
test suite as tests/sys/posixshm

Some other highlights:
- Convert the testcases over to ATF
- Don't use hardcoded paths to /tmp (which violate the ATF/kyua samdbox); use
mkstemp to generate temporary paths for non-SHM_ANON shm objects.

Sponsored by: EMC / Isilon Storage Division

Integrate tools/test/posixshm and tools/regression/posixshm into the FreeBSD
test suite as tests/sys/posixshm

Some other highlights:
- Convert the testcases over to ATF
- Don't use hardcoded paths to /tmp (which violate the ATF/kyua samdbox); use
mkstemp to generate temporary paths for non-SHM_ANON shm objects.

MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division

Integrate tools/test/posixshm and tools/regression/posixshm into the FreeBSD
test suite as tests/sys/posixshm

Copy ^/head@r289197 to ^/user/ngie/more-tests2

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

Add a set of regression tests for the POSIX shm API (shm_open(2) and
shm_unlink(2)).