[clang] [Clang] Fix name lookup for dependent bases (PR #114978)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

> > > @Endilll, please, could you take a look?
> > 
> > 
> > My knowledge of wording about templates is not deep enough, unfortunately.
> 
> Could you, please, suggest someone who can review this part?

I've already added several people who should be able to, but mind that we're very short on reviewers, so this will likely take time.

https://github.com/llvm/llvm-project/pull/114978