Binding generation for MLIR fails due to C++ being present

[vchuravy]

I currently don't have time to push this forward but the binding generator in https://github.com/JuliaLabs/MLIR.jl currently runs on top off #435 If I recall the issue the MLIR headers contain some C++ code that make generation fail.

@mofeing could you isolate some examples of what is failing here and maybe @Gnimuc has an idea on how to fix this properly instead of my hobbled together approach in #435