[llvm] LoopVectorize: add test for crash in #72969 (PR #74111)

[David Sherwood via llvm-commits]

david-arm wrote:

> Hi @david-arm,
> 
> Sorry I'm behind on my PRs: I'm currently on vacation, due to return to work in mid-March.
> 
> As for this PR, since the test is fine, I think we can merge it as-is, to document the failure. I'll try to pick up #74456 soon and complete it. What do you think?

Yeah, seems reasonable. And no rush to finish the other patch - enjoy your vacation!

https://github.com/llvm/llvm-project/pull/74111