- Renamed `cpp11_thread.cpp` to `thread.cpp`
- Removed features that are only supported by Win32 threads (`thread_wait` with timeout and mutex with spinlock)
- Fixed formatting in `thread.cpp`
This change removes timespec_get() from Unix systems and makes it also possible to cross-compile binaries on macOS Big Sur or macOS Monterrey that target macOS Mojave at minimum since Mojave lacks support for timespec_get().