[libcxx-commits] [libcxx] [libc++] Optimize unordered_{, multi}{map, set} move construct with allocators (PR #227955)

[Louis Dionne via libcxx-commits]

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

Please validate that our test coverage is sufficient before landing, but otherwise LGTM.

The benchmark results showing a regression seem to be a benchmark consistency issue, since we're not touching them.

https://github.com/llvm/llvm-project/pull/227955