[libcxx] [clang] [SemaCXX] Implement CWG2137 (list-initialization from objects of the same type) (PR #77768)

[via cfe-commits]

alexfh wrote:

> This is mostly just a call to coordinate a bit better. I would suggest that if the patch author is engaged on the thread, it would make sense to tell them the schedule on which you plan to revert so they have an opportunity to tell you if that's going to be disruptive.

This part captures one particular issue with my way of action I happened to miss. Thanks for putting this clearly @AaronBallman! Coordination was indeed far from perfect here. And your suggestion totally makes sense.

> While I realize this is the 'policy', I'm asking for compassion, particularly with new developers who are engaging.

This is also a good point @erichkeane. I'll try to consider this as well.

https://github.com/llvm/llvm-project/pull/77768