- Omit setrlimit_nthr testcase on FreeBSD (requires lwp.h, et al)
- Expect overflow with rlim_max at INT64_MAX, not UINT64_MAX (rlim_t is int64_t
on FreeBSD)

In collaboration with: pho
Sponsored by: EMC / Isilon Storage Division
Add limits.h #include for SSIZE_MAX

Sponsored by: EMC / Isilon Storage Division
Add limits.h #include for SSIZE_MAX

Sponsored by: EMC / Isilon Storage Division
Fix a typo (__FreeBSD__ -> __NetBSD__ when omitting setrlimit_nthr)
Mark signum __unused

Sponsored by: EMC / Isilon Storage Division