[libcxx-commits] [libcxx] [libc++] Diagnose unused variables of container types (PR #203084)

[Louis Dionne via libcxx-commits]

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

LGTM, but we need a release note and that release note should mention the escape hatch.

https://github.com/llvm/llvm-project/pull/203084