[clang] [CIR][AMDGPU] Add support for AMDGCN fcmp builtins (PR #198135)

[Ayokunle Amodu via cfe-commits]

ayokunle321 wrote:

> We probably should be deprecating these harder and emitting a warning

@arsenm Could you please elaborate? Deprecating the builtins?

https://github.com/llvm/llvm-project/pull/198135