[libcxx-commits] [libcxx] [libc++][ranges] Implement ranges::contains_subrange (PR #66963)

[Konstantin Varlamov via libcxx-commits]

https://github.com/var-const approved this pull request.

LGTM. Thanks a lot for pushing this through and addressing all the feedback!

https://github.com/llvm/llvm-project/pull/66963