[issue9035] os.path.ismount on windows doesn't support windows mount points

[Senthil Kumaran]

I see that ismount like function on windows is provide by the various
Win32 extensions. 

If Windows supported is added to ismount function itself, then it might be
a good idea to have attributes or list_attributes function as well.

But for posix, how will it be different from details provided by stat?
Would not it add redundancy?

Or would it be better to provide file attributes as part of stat
itself (if some are missing in Windows).