[llvm] [LV] Add a unittest to a failing scenario that should succeed (PR #196722)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

Could you update the title, as currently it is not really descriptive.

> I encountered the crash when I allowed the epilogue loop to have same VF as the main loop, given that the IC for the main loop is > 1.

Can this be tested end-to-end by forcing a scalable VF = 1 with IC= 1? It is not clear to me if/how this would be dependent on epilogue vectorization. Not sure, but I I thought having the same VF but different ICs should already be allowed.

https://github.com/llvm/llvm-project/pull/196722