[llvm] [Mips] Fix cttz.i32 fails to lower on mips16 (PR #179633)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon commented:

Are we not just missing a legality check inside CTTZTableLookup? I'd really like to avoid yet another TLI hack.

https://github.com/llvm/llvm-project/pull/179633