[llvm] [AArch64][llvm] Unify AArch64 tests into a single file (1/4) (NFC) (PR #146328)

[Jonathan Thackray via llvm-commits]

jthackray wrote:

> This series looks really good, thanks for working on it. Have all the tests been automatically converted or was it a manual process?

I've inherited these changes from @virginia-cangelosi who has moved teams now. The majority of these changes are hers, and I've added some new conversions, which I automated.

> How confident can we be that nothing has been missed in the conversion process?

That's my concern too, and I'm going through these diffs once more. Thanks for your comments, which I'll address (although it's more of a background task, so this PR won't be rushed). I hope we can have a consistent format going forward, since the current style and quality of the existing AArch64 varies.

https://github.com/llvm/llvm-project/pull/146328