[clang] [llvm] [DXIL] Set DXIL Version in DXIL target triple based on shader model version (PR #91407)

[David Peixotto via cfe-commits]

https://github.com/dmpots approved this pull request.

It would be nice to mention in the description what the sanitizer fix was compared to the original PR.

https://github.com/llvm/llvm-project/pull/91407