bug#25183: 26.0.50; expanding quoted file name on w32

[Eli Zaretskii]

> From: npostavs@users.sourceforge.net
> Cc: 25183@debbugs.gnu.org,  michael.albinus@gmx.de
> Date: Sat, 24 Dec 2016 13:51:14 -0500
> 
> For reference, on a GNU system, doing
> 
> $ echo xx > '~'
> $ emacs -Q '/:~'
> 
> opens up the $HOME directory, even though the "~" is not expanded by
> `expand-file-name'.

On MS-Windows, after I pushed my changes, the above opens the file
'~', not the home directory.  Not sure if we care, since we in effect
decided that this invokes undefined behavior.