llvm-project

e6974daa - [Clang][Concepts] Fix the constraint equivalence checking involving parameter packs (#102131)

[Clang][Concepts] Fix the constraint equivalence checking involving parameter packs (#102131) We established an instantiation scope in order for constraint equivalence checking to properly map the uninstantiated parameters. That mechanism mapped even packs to themselves. Consequently, parameter packs e.g. appearing in a function call, were not expanded. So they would end up becoming `SubstTemplateTypeParmPackType`s that circularly depend on the canonical declaration of the function template, which is not yet determined, hence the spurious error. No release note as I plan to backport it to 19. Fixes https://github.com/llvm/llvm-project/issues/101735 --------- Co-authored-by: cor3ntin <corentinjabot@gmail.com>