Log Message:
sysutils/rsyslog: also test for atomic ops on time_t.

This is to cater to 32-bit NetBSD ports, where time_t is also
(and has been for a long time) __int64_t.  Without this check,
__sync_bool_compare_and_swap_8 would end up being undefined when
linking rsyslog, since the compiler isn't obliged to supply that.
This causes the pthread / locking variant to be chosen on these
systems, but makes rsyslog build, at least.

(An earlier attempt at doing this only for time_t was met with
complications and was therefore abandoned.)

There's also just a single use of ATOMIC_CAS_time_t() in rsyslog...

Submitted upstream in
  https://github.com/rsyslog/rsyslog/pull/4994