[wrmsr]

It's stated that llvm ir is not stable (https://llvm.org/docs/DeveloperPolicy.html#ir-backwards-comp...) and in my relatively limited experience with it there have been enough differences between every little release to make decoupling even official frontend and backend versions not safe or reliable (much less bolting on and maintaining an unofficial backend impl). If bundling/pinning the flang/clang versions with the supported llvm ir version supported by the alternate backend is feasible (which seems sane) then I definitely agree this is an awesome capability (clang-on-sulong) but given how unapologetically volatile llvm ir is I wouldn't exactly call it 'free' :p (but still a lot better than writing a c++ frontend)