[PERF ONLY] Revert "Prefer visibility map parents that are not doc(hidden) first"

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -375,13 +375,9 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
             use std::collections::vec_deque::VecDeque;
 
             let mut visible_parent_map: DefIdMap<DefId> = Default::default();
-            // This is a secondary visible_parent_map, storing the DefId of
-            // parents that re-export the child as `_` or module parents
-            // which are `#[doc(hidden)]`. Since we prefer paths that don't
-            // do this, merge this map at the end, only if we're missing
-            // keys from the former.
-            // This is a rudimentary check that does not catch all cases,
-            // just the easiest.
+            // This is a secondary visible_parent_map, storing the DefId of parents that re-export
+            // the child as `_`. Since we prefer parents that don't do this, merge this map at the
+            // end, only if we're missing any keys from the former.
             let mut fallback_map: DefIdMap<DefId> = Default::default();
 
             // Issue 46112: We want the map to prefer the shortest
@@ -416,11 +412,6 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
                         return;
                     }
 
-                    if ty::util::is_doc_hidden(tcx, parent) {
-                        fallback_map.insert(def_id, parent);
-                        return;
-                    }
-
                     match visible_parent_map.entry(def_id) {
                         Entry::Occupied(mut entry) => {
                             // If `child` is defined in crate `cnum`, ensure
@@ -448,9 +439,8 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
                 }
             }
 
-            // Fill in any missing entries with the less preferable path.
-            // If this path re-exports the child as `_`, we still use this
-            // path in a diagnostic that suggests importing `::*`.
+            // Fill in any missing entries with the (less preferable) path ending in `::_`.
+            // We still use this path in a diagnostic that suggests importing `::*`.
             for (child, parent) in fallback_map {
                 visible_parent_map.entry(child).or_insert(parent);
             }