[llvm] [WIP] Separate Asan instrumentation in amdgpu-sw-lower-lds. (PR #134832)

[via llvm-commits]

b-sumner wrote:

> Yeah, that is the downside of always setting the attribute. I'm checking ways to set this "used" attribute only when asan is enabled. But I think device-libs would not have the information if asan is enabled or not.

Right, it does not.  But I thought this was about SW LDS?  Even then, we still don't know if these functions are used until we know that LDS is actually used.

https://github.com/llvm/llvm-project/pull/134832