[llvm] [GlobalOpt] Fix unreachable ifunc globalopt crash (#157332) (PR #157593)

[Nikita Popov via llvm-commits]

nikic wrote:

@hstk30-hw Please ensure that you drop any mentions from the commit description when merging changes. We'll be getting these notifications forever now.

https://github.com/llvm/llvm-project/pull/157593