[build] Stop assuming llvm is always the top-level in unified build#79342

kateinoigakukun merged 1 commit intoswiftlang:mainswiftlang/swift:mainfrom

kateinoigakukun:pr-5f633ca7d7738a3c949fbbe8d10d43996153eccbkateinoigakukun/swift:pr-5f633ca7d7738a3c949fbbe8d10d43996153eccbCopy head branch name to clipboard