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

[Jay Foad via cfe-commits]

jayfoad wrote:

> Keeping deprecated features in LLVM for some number of years facilitates bisecting LLVM against a specific UMD version and vice versa.

I get that, but the comment saying they're deprecated has been there for over 6 years. Maybe the problem is that no-one's ever going to notice that comment, and we need a more formal way of warning users that they're using a deprecated builtin?

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