swift234

IRGen: Don't nonlazily realize classes (unless they ask).

We lazily realize classes when we access their metadata now, so there's no need to force the ObjC runtime to do this greedily anymore, except for classes that the runtime statically references. For those cases, add an @objc_non_lazy_realization class attribute that will put that class reference in the nlclslist section.

Swift SVN r23105