[libcxx-commits] [libcxx] [libc++][NFC] Centralize test for support of == and != in ranges (PR #78481)

[Konstantin Varlamov via libcxx-commits]

https://github.com/var-const requested changes to this pull request.

Nice refactoring, thanks! Mostly LGTM except a couple minor comments (in addition to the existing feedback).

https://github.com/llvm/llvm-project/pull/78481