bug#15933: make check not working

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: 15933@debbugs.gnu.org,  andrewjmoreton@gmail.com
> Date: Wed, 20 Nov 2013 19:33:30 -0500
> 
> So in particular "emacs -L :/foo" would result in command-line-args
> containing ("-L" ";/foo")?

Almost: MSYS also replaces / with its Windows mapping (which depends
on where is the MSYS tree's root).  In my case, this gives

    ("-L" ";D:\usr\MSYS\foo")