bug#22534: File notify broken on Windows

[Eli Zaretskii]

> From: Fabrice Popineau <fabrice.popineau@gmail.com>
> Date: Thu, 11 Feb 2016 16:19:49 +0100
> Cc: Michael Albinus <michael.albinus@gmx.de>, 22534@debbugs.gnu.org
> 
> Some information regarding the original problem.

Thanks.

> The first diagnostic is that QueueUserAPC shouldn't fail with error 31.
> This happens because the worker thread is already terminating, but that does 
> not leave
> a chance for watch_end to run.

Aren't those the cases when the parent directory of the files being
watched is deleted?  If so, do you see how to prevent the thread from
terminating abnormally?