[llvm] [AArch64][SVE2] UZP should only have one result (PR #93041)

[David Green via llvm-commits]

davemgreen wrote:

Yeah it's worth adding as a test. That code has a number of things that looks like they could be simplified by the compiler, so it might not keep testing the same thing forever, but it's good to have so we know it doesn't break in the future.

I was wondering if we should just remove that bit of code, it must be quite rare for it to come up, the BuildVectors are more often turned into shuffles before they get to that point nowadays. Let me try some experiments.

https://github.com/llvm/llvm-project/pull/93041