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

[John McCall via llvm-commits]

rjmccall wrote:

So your users today are building for generic AMDGPU but using builtins that are only available on a specific processor release? Presumably that code is protected *somehow* and their programs are not simply crashing at runtime. Is that something you'd be able to leverage at all, or is completely ad hoc?

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