I don't think that STACK_GROWS_DOWNWARDS has any effect on WIN32 builds. I've had it in and out and it has made no difference.
More concerning is the hard-coding of things like -DHAVE_CHICKEN_CONFIG_H in
csc.scm.in. Since this isn't setup for windows who knows what might go wrong. Right now csc works ok with the following mods when it is run through sed as it is in the mingw makefile I attached.
***
csc.scm.in Line 105
removed the -DHAVE_CHICKEN_CONFIG define
Line 185
(define default-library-files '("%libdir%/libchicken.a"))
(define default-library-files '("%staticlibfiles%"))
Line 529
Removed -fPIC and -DPIC
By the way, I ran all of the benchmarks and they worked fine.