[clang] [llvm] [mlir] [AMDGPU] add clamp immediate operand to WMMA iu8 intrinsic (PR #171069)

[Muhammad Abdul via llvm-commits]

0xzre wrote:

> This can't just break existing uses. Needs to implement bitcode autoupgrade, and some compatibility on the builtin signature.
> 
> Also, can we just infer clamping as an optimization fold based on the use context?

Good catch. Will add a bitcode autupgrade for the old 4 op WMMA IU8 intrinsic to append clamp=0, plus a lit bitcode test. I'll keep source compatibility by keeping the existing builtin spelling mapped to clamp=0 and adding the 5 op form. Clamp inference can be a follow-up combine I think... this patch stays on correctness/compat. Would that be okay @arsenm ?

https://github.com/llvm/llvm-project/pull/171069