[llvm] [Hexagon] Add missing pattern for v8i1 type (PR #120703)

[Brian Cain via llvm-commits]

androm3da wrote:

> Does this fix #59009 ?

Kryzsztof's concern there was that the ABI was underspecified, so the fix was not clear, or rather any fix wouldn't be portable.

> The issue is that we'd need to amend the ABI, to either allow passing/returning boolean vectors, or specify the conversions. At the moment LLVM is (AFAIK) the only compiler targeting Hexagon with HVX, so we could get away with handling it internally to LLVM, but it would make it harder for other potential future compilers/code generators to be binary-compatible with LLVM.

https://github.com/llvm/llvm-project/pull/120703