[libcxx-commits] [libcxx] [libc++] Make `<map>` `std::multimap` constexpr as part of P3372R3 (PR #161901)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 approved this pull request.

LGTM with the LLVM23 added to the FIXME.

https://github.com/llvm/llvm-project/pull/161901