`std` docs has `equivalent` methods in the search index that lead nowhere

[Alexendoo]

I was checking if std exposed hashbrown::Equivalent and found these seemingly non existent methods

https://doc.rust-lang.org/std/index.html?search=equivalent

[zachs18]

It looks like the search results are present on 1.71.0's docs (and after), but not on 1.70.0's docs (or before)

[Alexendoo]

Seems that's when std's hashbrown was upgraded to the version that added the Equivalent trait - #111306