[clang] [PAC][clang] Implement address/type discrimination for VTT vtable pointers (PR #205808)

[Oliver Hunt via cfe-commits]

ojhunt wrote:

> Sure, I can add a release note. Just for my understanding, what makes this patch require one? I noticed similar changes in this area didn't include release notes.

I've given up deciding what warrants a release note, especially given the number of "crash" fixes that were innocuous assertion failures, but this is a full feature/abi addition that's definitely worth it.

https://github.com/llvm/llvm-project/pull/205808