bug#41242: Port feature/native-comp to Windows

[Eli Zaretskii]

> From: Nicolas Bértolo <nicolasbertolo@gmail.com>
> Date: Thu, 14 May 2020 16:48:06 -0300
> Cc: Eli Zaretskii <eliz@gnu.org>, 41242@debbugs.gnu.org
> 
> > As you said the problem is to decide who has the duty to remove the file
> > at last.  If each Emacs deposes a file says .foo.eln-pidxxx for the
> > whole time is using foo.eln should be easy for the last Emacs to
> > understand it is really the last and has to do the clean-up in the case
> > foo.eln was renamed in foo.eln*whatever
> 
> That file would be create when opening foo.eln, but when
> Emacs is closing we don't know what file it refers to:
> - foo.eln
> - foo.eln.old
> - foo.eln.old2
> - foo.eln.oldN
> 
> These last files could be created if foo.eln.old exists at the time of 
> renaming.

We could try deleting all of them.  Those that are still in use will
not be deleted.