[llvm] [SimplifyCFG] Fix hoisting problem in SimplifyCFG (PR #78615)

[Nikita Popov via llvm-commits]

nikic wrote:

Causes a crash in stage2 clang: https://llvm-compile-time-tracker.com/show_error.php?commit=e36825ea6feefeef44cca7710d775fba287d3fb2

https://github.com/llvm/llvm-project/pull/78615