[llvm] [AArch64][GISel] Translate legal SVE formal arguments and select COPY for SVE (PR #95236)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

I'm not 100% sure about all the RegBankInfo stuff, but we can change that if we need to later. From what I can tell this LGTM if the tests pass with a rebase.

https://github.com/llvm/llvm-project/pull/95236