_LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK should be made part of some hardening modes

[ldionne]

I believe that _LIBCPP_DEBUG_STRICT_WEAK_ORDERING_CHECK should be made part of some of the hardening modes. It is likely only suitable for the debug mode, although this ties into whether we allow complexity changes made by hardening modes.

[danlark1]

Given we check only for first 100 elements, it does not technically change the complexity of the algorithm

[ldionne]

Yeah, I think we want to make it part of the debug mode.

[tstellar]

Do we still need to backport a fix for this one?

[ldionne]

We're good, 8938bc0 is on release/18.x. I tagged these issues with the milestone before the branch to indicate that we wanted to merge those in time for the release.