[llvm] [AArch64][Vectorizer] Enable scalable factor-3 interleaving (PR #217370)

[Harry Ramsey via llvm-commits]

Harry-Ramsey wrote:

I followed the guide here: https://llvm.org/docs/TestSuiteGuide.html

So just `-C../llvm-test-suite/cmake/caches/O3.cmake`

https://github.com/llvm/llvm-project/pull/217370