478a33dabc
rustdoc: refine cross-crate impl inlining This changes the current rule that impls within `doc(hidden)` modules aren't inlined, to only inlining impls where the implemented trait and type are reachable in documentation. fixes #14586 fixes #31948 .. and also applies the reachability checking to cross-crate links. fixes #28480 r? @alexcrichton