[clang] Fix assertion failure during conversion function overload resolution. (PR #98671)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> > LGTM, but please add a release note so users know about the fix.
> 
> @AaronBallman Appreciate the reminder! Done.

Thanks! Do you need someone to land the changes?

https://github.com/llvm/llvm-project/pull/98671