[llvm] [AArch64] Improve code generation of bool vector reduce operations (PR #115713)

[Csanád Hajdú via llvm-commits]

Il-Capitano wrote:

Thanks for the quick reaction.

Two changes were required after the rebase:
* A small change was needed because of https://github.com/llvm/llvm-project/pull/117558. I replaced `-1` with `APInt::getAllOnes(32)`.
* A new test case was added that is affected by this change: `llvm/test/CodeGen/AArch64/vector-extract-last-active.ll`.

https://github.com/llvm/llvm-project/pull/115713