[PATCH] Add missing mingw-w64 case for Triple -> TargetInfo mapping

[Saleem Abdulrasool]

MinGW is no longer treated as an OS.  During the 3.5 cycle, we normalized the Windows triples.  MinGW is treated as an environment, the OS is Windows.  The resultant triple would be i686-windows-gnu or x86_64-windows-gnu.  Users are still able to pass the old triple, however, internally, we expect the normalized form now.

The cases you are adding here were intentionally removed during that change.  Please do not add these back.  In fact, we should remove MinGW from the OS enumeration.

What exactly are you trying to do that this is causing you an issue?

http://reviews.llvm.org/D4804