rustdoc doesn't show that a trait bound is `~const`

[camelid]

For example, see https://doc.rust-lang.org/nightly/std/intrinsics/fn.const_eval_select.html. The trait bounds for F and G each include ~const, and while the bounds themselves are shown, ~const is not.

[fee1-dead]

Related: #92229 helped by not showing ~const Drop. We don't really have a policy for documenting experimental features in rustdoc, since const_trait_impl is not yet accepted and ~const is still provisional syntax, this issue is probably currently unactionable.

[fee1-dead]

Coming back at this. Hiding const trait bounds was deliberate. const_trait_impl is provisional and its RfC was not approved. Showing an unstable syntax in rustdoc should be avoided.