[llvm] [SimplifyCFG] Skip threading if the target may have divergent branches (PR #100185)

[via llvm-commits]

hiraditya wrote:

Maybe all of this can be moved to Transforms/Scalar/JumpThreading.cpp ? simplifycfg is doing too many things which could be better suited as separate passes.

https://github.com/llvm/llvm-project/pull/100185