[llvm] [LoopUnroll] Fix block frequencies for epilogue (PR #159163)

[Joel E. Denny via llvm-commits]

jdenny-ornl wrote:

@Andarwinux Thanks for letting me know.

> Could you take a look at [this](https://github.com/llvm/llvm-project/issues/165998)? I used bisect to determine the crash was caused by this PR, but your fix doesn't seem to fully fix the problem I'm encountering.
> 
> To be precise, the original crash was fixed, but it subsequently crashed in the same manner elsewhere. Furthermore, it appears the problem doesn't occur as long as --pgso=false is not specified.

As I commented there, I need instructions to reproduce that bug.

> Now there's a simpler [reproducer](https://github.com/llvm/llvm-project/issues/166092).

That one seems to be resolved by PR #165938.



https://github.com/llvm/llvm-project/pull/159163