[llvm] [LLVM][AArch64] Correctly lower funnel shifts by zero. (PR #140058)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon commented:

getNode() already handles zero shift amounts for shifts and rotates - why not just add it for fshl/fshr as well?

https://github.com/llvm/llvm-project/pull/140058