[clang] [llvm] [AArch64][NEON] Add intrinsics for LUTI (PR #96883)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

To clarify for anyone else looking at this... there are three families of LUTI instructions: one uses NEON registers, one uses SVE registers, and one uses SME registers.  This patch is just the variant that uses NEON registers.

https://github.com/llvm/llvm-project/pull/96883