Class resilience part 2 #13297
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Class resilience part 2 #13297
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Two things here:
First, an NFC refactoring to metadata emission, which will be important later.
Second, moving some stuff to before the address point in generic class metadata. The dependent data area and field type vector slot are not ABI, but rather private storage used by the generic instantiation function and the field type vector function, respectively. By moving them before the address point, we ensure that the tail end of a generic class template, after the Objective-C area, consists entirely of null pointers. In a future patch, they can be omitted entirely.
More importantly, this means that for a class with a resilient base class, it suffices to initialize the tail area with the right size at runtime, without having to perform any kind of "sliding" of the dependent data.