[clang] [Clang][P1061] Add stuctured binding packs (PR #121417)

[Jason Rice via cfe-commits]

ricejasonf wrote:

@cor3ntin 

> Now that the Clang 20 branch has happened, I think we should go ahead with that PR

Does this mean we should adjust the cxx_status page to not say Clang 20? I also see there is a conflict with the ReleaseNotes.md where it appears all of the C++2c items no longer exist. (I guess that is because it is for the next release.)

> It would be great to explore merging ResolvedUnexpandedPackExpr and FunctionParmPackExpr in a separate PR. Is that something you would be interested in exploring?

I can look into this. I will consider `SubstNonTypeTemplateParmPackExpr` as well although I am not sure how special that one is.

>Thank you Jason for contributing this feature and for being reactive on this rather involved review :)

Likewise and thank you and the others for your contributions and diligence while reviewing this!

https://github.com/llvm/llvm-project/pull/121417