[clang] [llvm] [mlir] [AMDGPU] Add GFX12 WMMA and SWMMAC instructions (PR #77795)

[Anlun Xu via cfe-commits]

anlunx wrote:

Also need to be updated: https://github.com/llvm/llvm-project/blob/bb6a4850553dd4140a5bd63187ec1b14d0b731f9/llvm/lib/Target/AMDGPU/SMInstructions.td#L14 

https://github.com/llvm/llvm-project/pull/77795