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

[Paul Walker via llvm-commits]

paulwalker-arm wrote:

> The fact that Neon has LDP and postinc would feel like enough of a reason to favour Neon on a tie.

Whereas I'd say "The fact that Neon has LDP and postinc would feel like enough of a reason for NEON to have a lower cost when comparing equivalent vector lengths."

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