Mutually-circular type declarations for Clang.jl

Where is the latest info about mutually-circular type declarations (also called ‘mutually recursive type declarations’, also for structs).

Open issue in Julia since 2011. Latest info? Maybe “recursive field types, the easy version”? Any Pointers?

Reason is that Clang.jl generates wrong code:

struct b
    x::a
end

struct a
    self::Ptr{a}
    x::b
end