Actually looking at the dumped IR is usually not interesting, the tests just
need to get to that stage to be able to perform the validation
correctly. Additionally, the IR is very large for some of these tests, so
dumping it makes things sllooooowww when something fails.
The "subclass scope" is meant to represent a connection to a vtable (and how
public something needs to be), for things that end up in class
vtables. Specializations and thunks are mostly internal implementation details
and do not end up there, so subclass scope is not applicable to them. This stops
the thunks and specializations being incorrectly public.
(Note, there are some thunks that _are_ public facing: if a function has its
signature optimized, the original entry point becomes a thunk, and this entry
point is what ends up in vtables etc., so needs to remain around, which means
keeping the same hacks for `private` members of an `open` class.)
Fixes rdar://problem/40738913.
The non-deallocating destructor doesn't exists when dealloc can be overriden,
which means any class that inherits from a class defined in Objective-C. This
isn't necessarily all @objc classes, because of the
-disable-objc-attr-requires-foundation-module flag.
Fixes rdar://problem/40542246.
