How does Google deal with other projects' embedded code copies? ie some other project embeds a random old snapshot of LLVM, when you import that project into th

How does Google deal with other projects' embedded code copies? ie some other project embeds a random old snapshot of LLVM, when you import that project into the monorepo do you end up with two copies of LLVM, or do you strip the old copy and port the codebase to the current LLVM in the monorepo?