[libcxx-commits] [libcxx] [libc++] Implement part of P2562R1: constexpr `std::inplace_merge` (PR #129008)

[Mark de Wever via libcxx-commits]

https://github.com/mordante approved this pull request.

Thanks a few minor issues, otherwise LGTM!

https://github.com/llvm/llvm-project/pull/129008