[llvm] Unroll loops apple (PR #149358)

[Jon Roelofs via llvm-commits]

https://github.com/jroelofs commented:

Suggest adjusting the title to be a little more descriptive. Maybe something like:

> [aarch64] Tune unrolling prefs for ... on Apple CPUs

https://github.com/llvm/llvm-project/pull/149358