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

[via cfe-commits]

https://github.com/cor3ntin approved this pull request.

Now that the Clang 20 branch has happened, I think we should go ahead with that PR
 
- It would be great to explore merging ResolvedUnexpandedPackExpr and FunctionParmPackExpr in a separate PR. Is that something you would be interested in exploring?

- If there isn't any issue reported in the next ~ 2 weeks or so we should backport that to the Clang 20 branch

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

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