BUG/MINOR: threads: Fixes the number of possible cpus report for Mac.

There is no low level api to achieve same as Linux/FreeBSD, we rely
on CPUs available. Without this, the number of threads is just 1 for
Mac while having 8 cores in my M1.

Backporting to 2.1 should be enough if that's possible.

Signed-off-by: David CARLIER <devnexen@gmail.com>
1 file changed