[PATCH] [Clang] Implement basic MinGW32 version-independent installation detection

[Chris Kay]

>>! In D4177#4, @yaron.keren wrote:
> The patch must work with trunk to be accepted. The breaking changes are probably MinGW not being an OS anymore but an environment, you can test for it using isWindowsGNUEnvironment().
> 
> Have you compared to http://reviews.llvm.org/D3420 by martell/ruben ?

I'm afraid someone else will have to patch it for release then. I can't get trunk to build at all with or without the patch due to some major changes in the build system that I've been unsuccessful in patching for my system.

I have taken a look at ruben's patch but not extending Generic_GCC causes it to be significantly more complex than it needs to be as most of the logic //can// be transferred, contrary to what he states. It always uses hardcoded paths whereas this patch completely does away with them.

When I can get a working trunk build I'll give a shot at updating the patch.

http://reviews.llvm.org/D4177