[llvm-branch-commits] [clang] release/19.x: [Clang][Concepts] Fix the constraint equivalence checking involving parameter packs (#102131) (PR #106043)

[Younan Zhang via llvm-branch-commits]

zyn0217 wrote:

> Is this a major fix or regression fix?

It is a follow-up fix for the previous bug fix incorporated in 19. https://github.com/llvm/llvm-project/commit/04d20b17050203e07394b4f9ee61b5affe2d5347

But this isn't a regression since clang wasn't working properly in such cases, nor a major fix as I don't think it would affect much but rather ensure more correctness.

We have a report from @yuxuanchen1997 that some production codes rely on this to compile, so I think it merits a backport.


https://github.com/llvm/llvm-project/pull/106043