[llvm-branch-commits] [SimplifyCFG] Fix profcheck failure from #213302 (PR #220811)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/220811

This patch fixes the profcheck failure from that patch by explicitly
updating the branch weights given we can infer what the values should
be.