[Bug 38380] OSX Wine64 compile hangs on /dlls/ntdll/relay.c with gcc4.9

https://bugs.winehq.org/show_bug.cgi?id=38380

--- Comment #14 from Sergey Isakov  ---
(In reply to Josh Pettus from comment #13)
> At the time, clang could not compile wine64 due to the lack of 
> builtin_ms_va_list
>
> A few months ago, the patch to implement it finally was added to llvm master
> branch.  I've been compiling 64bit versions of wine for a little bit now.

My proposition is to use clang ONLY for winemac.drv. It doesn't need
builtin_ms_va_list.