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

[Matt Arsenault via cfe-commits]

arsenm wrote:

> [deprecated](https://github.com/llvm/llvm-project/blob/4f339eedfce6cc7bf8ea9f6737224629dd6e7d0b/clang/include/clang/Basic/BuiltinsAMDGPU.td#L316)

They should be deprecated, but that doesn't mean we can just remove them. There's no warning or anything if they are used 

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