Hi!

I created a mingw32 cross build for guile-2.0 some time ago, expecting
to need it real soon for "work" or for LilyPond.  Neither need
materialized until now; but it very soon.

Luckily, I found that Mike Gran did quite some work this spring on their
wip-mingw-guile-2.2 branch; so I packaged the latest snapshot.

Not sure if we want this in Guix -- but here it is.  I did a simple test
under wine and it seems to work.

janneke