Calls to objc_superclass detect the two struct items in the first argument as seperate variables, resulting in incorrect lifting

[0cyn]

This decompilation is incorrect:

The correct output can be seen here:

The first argument of objc_msgSendSuper2 is an objc_super struct containing a pointer to the self Class object and a pointer to the superclass.

The full type definitions can be seen starting here: https://github.com/apple-oss-distributions/objc4/blob/main/runtime/message.h#L34

[bdash]

This was fixed for the shared cache back in #6565. I brought that over to the unified Objective-C workflow in #7299.