New review comment by classabbyamp on void-packages repository

https://github.com/void-linux/void-packages/pull/38851#discussion_r954212154

Comment:
where is `cpu_set_t` put under `#ifdef _GNU_SOURCE`? `_GNU_SOURCE` does not exist anywhere in either `sched.h` nor `cpu-set.h`. Because of this, I think `__GLIBC__` is the correct way