[llvm] [AArch64][SVE] Handle consecutive Predicates in CC_AArch64_Custom_Block (PR #90122)

[Cullen Rhodes via llvm-commits]

https://github.com/c-rhodes approved this pull request.

Thanks for the patch.

I was wondering where this code kicks in for Z regs as I couldn't see any tests with arrays, but it's used for tuples of scalable vectors like in `@foo1`  in `llvm/test/CodeGen/AArch64/sve-calling-convention-mixed.ll`.

LGTM cheers, but I'll add another reviewer since I don't work on the backend much at the moment. So please wait before landing.

https://github.com/llvm/llvm-project/pull/90122