[clang] [Sema] Note member decl when initializer list default constructs member (PR #121854)

[Shafik Yaghmour via cfe-commits]

https://github.com/shafik commented:

Thank you for the fix. 

At a first glance this seems to make sense to me, I added some more reviewers.

Please add a release note.

https://github.com/llvm/llvm-project/pull/121854