[llvm] [AArch64] Coalesce the perfect-shuffle table (PR #202617)

[Alexis Engelke via llvm-commits]

aengelke wrote:

Can we move this to a .cpp file instead?

Also, I saw that you opened a lot of pull requests in a short time. Were some of these AI/LLM-assisted? If so, [you have to disclose this](https://llvm.org/docs/AIToolPolicy.html). Also, please shorten the PR descriptions and remove unnecessary information.

https://github.com/llvm/llvm-project/pull/202617