Specifically:
1. Fix the error message so that when we say you can't have a deinit that a
deinit can be on a noncopyable type along side a class or an actor.
2. Even though we already error on @objc enums and say they cannot be
noncopyable, we did not emit an error on the deinit saying that @objc enums
cannot have a deinit. I put in a nice to have error just to make it even
clearer.
rdar://105855978
rdar://106566054
7856f2d83d only partially skipped writing
out destructors when they were invalid, ie. it skipped writing the decl
itself but not the records common to all decls. This would cause any
records on the destructor to be applied on the next serialized decl.
Make sure to skip serializing anything to do with the destructor when
it's invalid and does not have a class context.