[llvm] [DirectX] Convert debug values to old style (PR #192162)

[Harald van Dijk via llvm-commits]

hvdijk wrote:

With LLVM `main` already having the option to build `dxil-dis`, I'm guessing it's better to update this to not use an external `dxc` binary and to use that instead. I'll update the PR.

https://github.com/llvm/llvm-project/pull/192162