[llvm] [SimplifyCFG] Updated early exit in `CanRedirectPredsOfEmptyBBToSucc` (PR #142582)

[via llvm-commits]

sharkautarch wrote:

@kper 
> I've forgot to run -O3. It seems that the EarlyCSEPass drops the merge and afterwards the SimplifyCFG pass is executed and removes the for.inc295 block.


Lol, I just now realized that `%storemerge739.lcssa761` never had any instructions using it to begin with, so the phi & `%storemerge739.lcssa761` was always trivial to remove (it probably was used in the original non-reduced form tho…)

https://github.com/llvm/llvm-project/pull/142582