bug#15933: make check not working

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Date: Wed, 20 Nov 2013 13:56:40 -0500
> Cc: 15933@debbugs.gnu.org
> 
> Glenn Morris wrote:
> 
> > I see nothing mingw specific in the changes you suggest,
> 
> Well, apart from the XARGS_LIMIT thing, which if needed would imply that
> make check has never worked on mingw.

It could have worked when there were fewer tests.