[clang] [clang][CGObjC] Sign the v-table pointer in ObjC exception RTTI. (PR #135562)

[John McCall via cfe-commits]

https://github.com/rjmccall commented:

LGTM, but I've fixed the release note: this is about the Objective-C exceptions ABI, not a general `type_info` thing for Objective-C++.

https://github.com/llvm/llvm-project/pull/135562