64-bit Guile on Windows

[Thomas Thiriez via General Guile related discussions]

Hi,

I am currently porting a macOS application to Windows, and need to 
have libguile working.

I can see GnuCash works with Guile. I could borrow their 
libguile.dll, but it is a 32-bit build, and I am making a 64-bit 
application. I tried building Guile 3, but had more success with 
Guile 2.2, so I will keep that version.

I have cross compiled it on my mac with mingw, and it kind of 
works. The only thing is that if I compile my .scm files to .go, 
then my fixnums are not automatically converted to big nums, and I 
get things like that:

(* 999 999 999) -> -76738825

My fix is to keep the .scm files, and avoid compiling to .go.

I believe this has something to do with the fact that, on that 
platform, we have:

sizeof(SCM)  == 8
sizeof(long) == 4

Is there something to do about that problem? Is there something I 
can do to have a working 64-bit Guile on Windows?

Thanks a lot for any help you could provide.

Regards,
Thomas Thiriez