It may be worth looking into providing an implementation of AccessControl on Unix. It would at least be nice to have some control over basic RWX permissions for user/group/all, or we could go deeper with getfacl and setfacl. Most of the things on Windows would likely have to be left out as it would be too far a stretch to map them to anything on Unix, but it's worth considering regardless.

discussion started in dotnet/corefx#8930.