Tracking issue for const `Ordering` methods

[CDirkx]

Constify methods of core::cmp::Ordering under feature const_ordering.

Current methods made const:

• reverse
• then

Tracking issue for const fn: #57563.

[pnkfelix]

Visiting for T-compiler steering backlog bonanza

Its not totally clear what this issue is meant to be tracking.

The description lists a pair of methods that were already made const in #75463.

We suspect the intent is to track the constification of the remainder of the Ordering methods that can be made const, but there's no clear specification of what the work items there are.

@rustbot label: S-tracking-need-summary

[CDirkx]

This issue was originally created as a tracking issue for constifying reverse and then under the feature const_ordering. However, these methods were insta-const-stabilized, skipping rustc_const_unstable(feature = "const_ordering", issue = "76113"). This issue has thus never actually been referenced in the Rust codebase.

I agree that constifying the remainder of Ordering is a good idea, but not something I myself can work on right now. I could therefore close this issue for now, and if someone else starts working on further constification a new tracking issue could be opened.