Global Registration (a kind of pre-rfc)

[Vorpal]

@josh

I personally suspect we'll end up going the fully static compile-time approach, with the assumption that dynamically loaded modules will need a different kind of dynamic registration mechanism. For instance, modules might need to provide some kind of metadata, or modules might have to make a call to register themselves.

How will this work in staticlibs integrated into C/C++ projects given that the linker is free to discard unreferenced objects / sections? And that it is a foot gun in C++ to do static constructor based registration already. How will this work across multiple rust staticlibs linked into the same C/C++ project?