[clang] [clang-tools-extra] [clang] Concepts: support pack expansions for type constraints (PR #132626)

[Younan Zhang via cfe-commits]

https://github.com/zyn0217 commented:

Thanks for working on it.

The patch looks good overall, but as you've suggested that this is incomplete, I think we want to go over it again after the cache part gets adapted.

I left a question, for which we probably want an assertion there.

https://github.com/llvm/llvm-project/pull/132626