Function rustdoc::passes::collect_intra_doc_links::traits_implemented_by

fn traits_implemented_by(
    cx: &mut DocContext<'_>, 
    type_: DefId, 
    module: DefId
) -> FxHashSet<DefId>

Given a type, return all traits in scope in module implemented by that type.

NOTE: this cannot be a query because more traits could be available when more crates are compiled! So it is not stable to serialize cross-crate.