RFC: Update Mac OSX stack patch

[Nick Burns]

I recently found genpatch. Wow, wowey wow wow. Very sleek
Used this line to gen the attached patch
./tools/genpatch -v -n winePatchMacOSXStackUpdate -c "Mac OSX stack update" 
-m "include/msvcrt/process.h tools/winegcc/winegcc.c"

Anyway -- this patch is very simple and just extends the work that was done 
before to other places where stdcall and cdecl can be defined

This makes sure they are all consistent and not misdefined (leading to 
runtime failures)

And lastly -- any comments welcome...
Ill try and follow this patch -- and at somepoint work on my openal patch 
(which did not go over too well last time.... poor openal -- there there I 
still like you)

- Nick