[clang] [ObjC] Check entire chain of superclasses to see if class has fixed offsets (PR #81335)

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AtariDreams wrote:

Layout before and after my change:
<img width="854" alt="Screenshot 2024-02-10 at 6 55 53 PM" src="https://github.com/llvm/llvm-project/assets/83477269/6e45ad11-16e8-4dcc-8d7b-f8e29a1a9cc0">


https://github.com/llvm/llvm-project/pull/81335