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

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alexfh wrote:

Given the broad impact we see in our code, I suppose this can affect other users as well. I suggest to revert first and then find a proper solution.

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