Julia doesn't tick the "compile to .o/.h" box. As far as I can tell, the use case for AOT Julia is avoiding package compilation overhead, not delivery of standalone code objects.
_edit_ seems JuliaC does support this sort of thing:
Julia does already support this kind of thing. Moreover with a minuscule fraction of the money that’s being poured into making Swift usable for data science and machine learning, truly top notch support for generating standalone binaries from Julia could readily be developed. Which is kind of frustrating but what can you do?