[llvm] [DirectX] Lower DbgAssign to DbgValue (PR #200267)

[Harald van Dijk via llvm-commits]

hvdijk wrote:

The Windows CI failure is unrelated and covered by #202255, but given that the HLSL tests are also failing for unrelated reasons, even if it gets approved, I'd rather wait for CI to be stable and wait to see the tests pass again before merging this.

https://github.com/llvm/llvm-project/pull/200267