[llvm] [AArch64][GlobalISel] Basic SVE and fadd (PR #72976)

[David Green via llvm-commits]

davemgreen wrote:

I was rebasing this yesterday but didnt get as far as pushing it apparently.

I think it might be good to get it in so there is some testing for scalable vectors, even if it's relatively bare bones at the moment. As for fully supporting all the operations, that would be a lot of work and it might be best to keep focussing on the base architecture for the time being. The option lets us keep this as something that can be worked on in the background.

https://github.com/llvm/llvm-project/pull/72976