[llvm] [LV][AArch64] Prefer Fixed over Scalable if cost-model is equal (Neoverse V2) (PR #95819)

[Sjoerd Meijer via llvm-commits]

sjoerdmeijer wrote:

To create a new baseline, I have merged the TTI changes in here (and addressed the minor comments).

I have not yet added more logic to preferFixedIfEqualToScalable, but I am struggling a little and I have (unsurprisingly) a lot of sympathy for Dave's remark about this looking a bit over-engineered, but will give it another try as this is what I promised to do.

https://github.com/llvm/llvm-project/pull/95819