[clang] [compiler-rt] [clang][CodeGen] Model vtable pointer as TBAA member of polymorphic types (PR #209053)

[Gustas Janušonis via cfe-commits]

================

----------------
LeGusto wrote:

Not sure if this test is warranted now since I updated two older tests to expect the vtable pointer

https://github.com/llvm/llvm-project/pull/209053