New review comment by dkwo on void-packages repository

https://github.com/void-linux/void-packages/pull/41844#discussion_r1122342284

Comment:
The `gethostbyname_r` and `strerror_r` are different in gnu and posix. The original code tries to check this with `!defined(_GNU_SOURCE)`, but maybe something else is turning on `gnu_source`?