[clang] [CIR] Implement vTableClassName for Type::ObjCObject (PR #195232)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor commented:

I'm honestly a bit surprised that the test case here compiles. I don't think we've really done anything to support Objective-C. Is there a reason that you're implementing this, beyond just wanting to contribute to the open GitHub issue?

https://github.com/llvm/llvm-project/pull/195232