Add tests for #2398

Author: topecongiro

tests/source/visibility.rs

@@ -0,0 +1,8 @@
+// #2398
+pub mod outer_mod {
+    pub mod inner_mod {
+       pub ( in outer_mod ) fn outer_mod_visible_fn() {}
+         pub ( super ) fn super_mod_visible_fn() {}
+      pub ( self ) fn inner_mod_visible_fn() {}
+    }
+}

tests/target/visibility.rs

@@ -0,0 +1,8 @@
+// #2398
+pub mod outer_mod {
+    pub mod inner_mod {
+        pub(in outer_mod) fn outer_mod_visible_fn() {}
+        pub(super) fn super_mod_visible_fn() {}
+        pub(self) fn inner_mod_visible_fn() {}
+    }
+}