* Fix build on NetBSD
Notably:
1. A typo in `f_flag` vs `f_flags` - this was probably never tested
2. Some pointless name differences - `st_mtimensec` vs
`st_mtime_nsec`
3. The big one: This said that LC_GLOBAL_LOCALE() was -1 "everywhere".
Well, not on NetBSD.
* ifdef for macos