I suggested a while back pruning win-mac.h and removing some macros, but met with 
resistance because, roughly, "someone might be using them".  (This is why, when working on 
cross-platform stuff with per-platform macros or whatever, I've avoided using win-mac.h and 
put Windows support into other internal headers.)

I still think it would be a good idea.  But, I'm still not the Windows maintainer....