[PATCH v2] osutil: add darwin-only version of os.listdir using cffi

[Jun Wu]

Excerpts from Maciej Fijalkowski's message of 2016-07-15 09:58:59 +0200:
> I would prefer for setup.py not to grow indefinitely (it's already
> huge) which directory you want it?

I think reviewers with push access can answer this question better.
Personally I feel you will get less objections and move faster if just use
setup.py (scope the logic in a function or class).

> cffi does not support __attribute__(packed), so we can't define it
> like that (maybe there is a better way)

Seems it supports now?
https://bitbucket.org/cffi/cffi/commits/c5e17441bc96