[clang] [llvm] [LLVM] Add intrinsics for v_cvt_pk_norm_{i16, u16}_f16 (PR #135631)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

There seem to be scalar versions of these instructions, but no matching intrinsics? I would hope we would have both (and combines to form the vector case from the scalar uses, and breaking the vector case into scalar for partially undef)

https://github.com/llvm/llvm-project/pull/135631