[clang] [llvm] [AMDGPU][clang][CodeGen][opt] Add late-resolved feature identifying predicates (PR #134016)

[John McCall via llvm-commits]

rjmccall wrote:

An intrinsic seems like the right IR model for CPU recognition, even for targets that don't specifically need to late-resolve it. That should be much easier for passes to optimize based on CPU settings than directly emitting the compiler-rt reference in the frontend. I know that generating IR with conservative target options and then bumping the target CPU in a pass is something various people have been interested in, so late optimization is specifically worth planning for here.

https://github.com/llvm/llvm-project/pull/134016