Bug Fixes
---------

- Make <sys/cpuset.h> safe for c89 compilations.
  Addresses: https://cygwin.com/pipermail/cygwin-patches/2023q3/012308.html

- Make gcc-specific code in <sys/cpuset.h> compiler-agnostic.
  Addresses: https://cygwin.com/pipermail/cygwin/2023-July/253927.html

- Fix AT_EMPTY_PATH handling in fchmodat and fstatat if dirfd referres to
  a file other than a directory
  Addresses: https://cygwin.com/pipermail/cygwin-patches/2023q2/012306.html