Issues with System.Posix.Files

[David Brown]

Hi, I'm writing some code to use System.Posix.Files to restore a
filesystem.  I've discovered a few missing things.

  - There is a createDevice, but the mode values needed to pass to
    this call aren't exported (blockSpecialMode,
    characterSpecialMode).

  - In fact, it would be nice to be able to have fileTypeModes
    exported as well as each of the types.  One would assume that
    someone using System.Posix wishes to access things at this kind of
    level.

Thanks,
David Brown