[clang] [Clang] Support using boolean vectors in ternary operators (PR #154145)

[Erich Keane via cfe-commits]

erichkeane wrote:

> > This needs a release note, else I think this is fine. LGTM.
> 
> I added one under the non-comprehensive changes. Should I put it somewhere more specific?

Nope, that was me mis-reading the Github interface.  LGTM.

https://github.com/llvm/llvm-project/pull/154145