Privacy: enqueue type alias

compiler/rustc_privacy/src/lib.rs

@@ -783,7 +783,7 @@ fn enqueue_def_id(&mut self, def_id: LocalDefId) {
                 }
             }
 
-            DefKind::TraitAlias | DefKind::Fn => {
+            DefKind::TraitAlias | DefKind::Fn | DefKind::TyAlias => {
                 self.ev.queue.insert(def_id);
             }
 
@@ -808,7 +808,6 @@ fn enqueue_def_id(&mut self, def_id: LocalDefId) {
 
             // Can't be reached
             DefKind::Impl { .. }
-            | DefKind::TyAlias
             | DefKind::Field
             | DefKind::Variant
             | DefKind::Static { .. }

tests/ui/privacy/reach-type-alias-issue-156778.rs

@@ -0,0 +1,20 @@
+//@ check-pass
+#![feature(lazy_type_alias)]
+
+use src::hidden_core;
+mod src {
+    mod aliases {
+        use hidden_core::InternalStruct;
+        pub type ExposedType = InternalStruct<f32>;
+    }
+    pub mod hidden_core {
+        use super::aliases::ExposedType;
+        pub struct InternalStruct<T> {
+            _x: T,
+        }
+        pub fn new() -> ExposedType {
+            InternalStruct { _x: 1.0 }
+        }
+    }
+}
+fn main() {}