Since some of the users of `CodeExtractor` like `HotColdSplitting` run late in the pipeline, returns are not cleaned to `unreachable`. So, just emit `unreachable` directly if the function is `noreturn`. Closes #84682
Since some of the users of `CodeExtractor` like `HotColdSplitting` run late in the pipeline, returns are not cleaned to `unreachable`. So, just emit `unreachable` directly if the function is `noreturn`. Closes #84682