[clang] [Sema][ObjC] Loosen restrictions on reinterpret_cast involving indirect ARC-managed pointers (PR #144458)

[John McCall via cfe-commits]

https://github.com/rjmccall requested changes to this pull request.

This all looks good to me. Please add a release note saying that we fixed an issue where the implementation was stricter than the ARC specification said. Also, I know that you had some questions around `const` and other qualifiers while implementing this; did you want to reflect those as test cases?

https://github.com/llvm/llvm-project/pull/144458