rustdoc: Process extern impls in all loaded crates

including those loaded through hacks.

Author: petrochenkov

src/librustdoc/passes/collect_intra_doc_links/early.rs

@@ -48,7 +48,6 @@ pub(crate) fn early_resolve_intra_doc_links(
     link_resolver.resolve_doc_links_local(&krate.attrs);
     link_resolver.process_module_children_or_reexports(CRATE_DEF_ID.to_def_id());
     visit::walk_crate(&mut link_resolver, krate);
-    link_resolver.process_extern_impls();
 
     // FIXME: somehow rustdoc is still missing crates even though we loaded all
     // the known necessary crates. Load them all unconditionally until we find a way to fix this.
@@ -58,6 +57,8 @@ pub(crate) fn early_resolve_intra_doc_links(
         link_resolver.resolver.resolve_rustdoc_path(extern_name, TypeNS, parent_scope);
     }
 
+    link_resolver.process_extern_impls();
+
     ResolverCaches {
         markdown_links: Some(link_resolver.markdown_links),
         doc_link_resolutions: link_resolver.doc_link_resolutions,