[llvm] [AArch64] Set MaxInterleaving to 4 for Neoverse V2 (PR #100385)

[Florian Hahn via llvm-commits]

fhahn wrote:

> > Here's a first version of a patch for epilogue vectorisation: [6b0f7de4f3347b7b5fc6362e7aa7764465501dfb](https://github.com/juliannagele/llvm-project/commit/6b0f7de4f3347b7b5fc6362e7aa7764465501dfb) considering VF x UF when checking profitability of epilogue vectorisation and adjusting the cost model accordingly (the main idea is to use the known upper bound for the trip count of the epilogue). There's also some accompanying microbenchmarks here [1e1576e6cb1f09965c3e7520c5a51958508df23b](https://github.com/juliannagele/llvm-test-suite/commit/1e1576e6cb1f09965c3e7520c5a51958508df23b). Let me know what you think!
> 
> Thanks for working on this @juliannagele ! It's probably best if you open a merge request, then we can continue that discussion there.

@juliannagele is OOO till end of next week unfortunately. @sjoerdmeijer @davemgreen  any chance you could check if the commit fixes the regressions that were mentioned earlier here?

https://github.com/llvm/llvm-project/pull/100385