bug#27986: 26.0.50; 'rename-file' can rename files without confirmation

[Eli Zaretskii]

> Date: Mon, 14 Aug 2017 18:34:30 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: p.stephani2@gmail.com, 27986@debbugs.gnu.org
> 
> There's nothing easier than implementing renameat_noreplace on
> MS-Windows, since the underlying system call does that by default, and
> it's emulating the Posix behavior that requires complications.  In
> fact, we already have this implementation: see sys_rename_replace (in
> w32.c) which needs to be called with its last argument FALSE (modulo
> the "at" part, which is easily handled).

Which I just did.