Guile 64-bit Windows support, redux

[Mike Gran]

Hello Guile,

There have been a few times where I made Guile work on 
MinGW -- usually the 32-bit, unthreaded variety -- because I wanted it
for my own entertainment.  Often around the time of the Lisp Game Jam.
The Game Jam just happened, so I was poking it again.  Although
I never actually delivered my game this year.

Janneke has also poked at Windows support a few times as well, and
he actually got it to run on 64-bit Windows.

I'd be willing [1] to update the patches for MinGW support for
review and inclusion into the main branch
for 3.0.10 or 3.2 but, only if maintainers are open, in principle,
to committing the most disruptive patch: the one where all
long integers become intptr_t to deal with Window's stupid
4-byte longs on 64-bit OSs.  Without agreeing on that as a
possibility, 64-bit Windows support is DOA.

There are a couple of slightly outdated versions of janekke's 64-bit patch.
Here, for example:

https://git.savannah.gnu.org/cgit/guile.git/commit/?h=wip-mingw&id=76950b4281c7dfff78b9ead6d3d62c070bbc1f13

Lately, with GitHub providing decent zero-cost Windows images
for their CI/CD actions, it should be possible to do a nightly pull
and 'make distcheck' off the main branch for Windows, Ubuntu,
and MacOS, without requiring the developer to use non-free tools
directly.  (But lots of non-free Javascript and who-knows-what on
GitHub's side of things.)

If this could be set up, it might stop the Windows build from getting
stale so quickly.

Also, it might be that this isn't worth doing.  After all, you can run
Guile on Cygwin and Guix on WSL on Windows 10/11 already. 
But some projects that depend on Guile do deliver on
Windows using customized versions of 2.2 or 1.8.

Let me know what you think.

-Mike Gran

[1] Last two times I volunteered myself for something on Guile/Guix,
I got quite ill. Let's not hope for a repeat.