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

[David Sherwood via llvm-commits]

david-arm wrote:

Just to be clear, I'm not against the idea of having a flag or enabling it by default on neoverse-v2, but I am just a bit nervous about any problems it may hide that we could be usefully fixing, that's all.

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