[llvm] [SLP]Exclude non-profitable subtrees. (PR #162018)

[Prabhu Rajasekaran via llvm-commits]

================

----------------
Prabhuk wrote:

Thanks @alexey-bataev for getting back to me. I am trying to get a reproducer hopefully by end of today. It is a bit of a complex build to reproduce locally and I am doing my best. Given this is a holiday week can you please consider reverting this change. I will work with you to debug the crash and help reland this change. This will help us turn our builders green. Thank you. 

https://github.com/llvm/llvm-project/pull/162018