[llvm] [LV] Transform tests for early-exit with stores (PR #183288)

[Andrei Elovikov via llvm-commits]

eas wrote:

> > Could you also add the VPlan printing test?
> 
> Done, though there's obviously no vplan generated at the moment.

Maybe it would be possible to use https://github.com/llvm/llvm-project/pull/178522 to have some basic VPlan dump here that the actual PR can "diff" against?

https://github.com/llvm/llvm-project/pull/183288