[clang] [llvm] [HLSL][DXIL] InterlockedOr and InterlockedOr64 builtins (PR #180804)

[Alexander Johnston via llvm-commits]

Alexander-Johnston wrote:

> ⚠️ undef deprecator found issues in your code. ⚠️

Currently the atomicBinOp DXIL operation expects `undef` in any coordinate not being used. Here's an example of all the different coordinate layouts https://godbolt.org/z/saqYb5Mzc
Given this it seems a usage of undef is required somewhere, and it seems easiest to produce the undef in Clang and to keep the DXILOpLowering changes simple, rather than to pass through poison values then replace them later.
I'm happy to alter to poison values and replace during DXILOpLowering if this would be better.

https://github.com/llvm/llvm-project/pull/180804