CodeGen.Platform.hs not including ghcautoconf.h as it should, breaks ARMv5 compiler
MachRegs.h requires ghcautoconf.h to be included before it, because, in the case of ARM processors, it needs to know what ARM variant is being used.
This patch fixes that in includes/CodeGen.Platform.hs, otherwise there is a mismatch between the compiler and llvm.
Perhaps it needs to be made more robust by instead including ghcautoconf.h from MachRegs.h? Otherwise someone else could easily break it. I originally didn't do this, because it wasn't done anywhere else.
Suggested fix attached.