[llvm] [EarlyIfConverter] Fix reg killed twice after early-if-predicator and ifcvt (PR #133554)

[Afanasyev Ivan via llvm-commits]

ivafanas wrote:

@MaskRay @jroelofs @fhahn @jmmartinez 

Could you please review the PR?


@MaskRay 

Could you also please check the correctness of transformation for Hexagon. It seems suspicious, that `early-if-predicator` has generated two equal instructions (I'm not familiar with Hexagon). This issue is not related to the one addressed in PR, but, imho, it needs some attention.

https://github.com/llvm/llvm-project/pull/133554