[llvm] [NFC] Reorder test lines in arith-fp-frem.ll (PR #79991)

[Paschalis Mpeis via llvm-commits]

paschalis-mpeis wrote:

@mgabka it felt more easy to 'parse with the eye' some updated costs (a PR will open  after this).

I added the `NO-VECLIB` cases on top, as those keep increasing with higher VFs regardless of architecture.
The rest is still NEON/SVE split.

But that's a matter of preference I guess.
I could add 2 comments explaining this, but if you are still not convinced we could scrap this I guess. :)

https://github.com/llvm/llvm-project/pull/79991