Certainly for all. I was mostly thinking in terms of e.g. languages that (can) compile to LLVM, since you have the intermediate form already defined. But then languages layer quite a lot on top of LLVM in terms of abstractions and safety constraints that make it probably a bad intermediary even for that subset. Even just for one language, there must be something funuseful that can be done just by viewing the same code with different syntaxes.