src/test/rustdoc/issue-27362.rs does not pass on beta

[brson]

cc #32017

This test is checking for nightly-specific behavior in rustdoc (that const fn is displayed), but when gating is on, rustdoc does not display const fn, so the test fails.

[alexcrichton]

cc #31329, the PR where this behavior changed
cc @quodlibetor (author)

[Mark-Simulacrum]

I'm going to close this issue as a duplicate of #13745, which tracks a number of tests which are currently ignored. It doesn't seem all that useful to track them separately, but let me know (and reopen) if we don't want this.