[llvm] CallSiteSplitting: Replace -callsite-splitting-duplication-threshold cl::opt with pass parameter (PR #223479)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Instead of converting, do we just want to remove? Is anyone using this option?

https://github.com/llvm/llvm-project/pull/223479