[clang] [llvm] [AMDGPU] Remove icmp and fcmp intrinsics and builtins (PR #208183)

[Marek Olšák via cfe-commits]

marekolsak wrote:

Are ballots implicitly prevented from being moved into a predecessor or successor basic blocks with a different EXEC mask, and are CFG restructuring passes tamed around ballot to make sure they don't affect the EXEC mask for it?

https://github.com/llvm/llvm-project/pull/208183