[clang] [llvm] [clang-tools-extra] [AMDGPU][GFX12] Add 16 bit atomic fadd instructions (PR #75917)

[Mariusz Sikora via cfe-commits]

mariusz-sikora-at-amd wrote:

What is the plan for atomic_{flat/ds/global}_bf16 builtins ? Right now they are accepting <2 x i16> instead of <2 x bfloat>. Do we want to create new builtins or we want to override them to accept both <2 x i16> and <2 x bfloat> ? 

https://github.com/llvm/llvm-project/pull/75917