Partially undo the fix of issue #30159 in PR #30294 to avoid breakage.

src/librustc_resolve/resolve_imports.rs

@@ -871,6 +871,9 @@ fn merge_import_resolution(&mut self,
                             is_public: is_public
                         };
                     }
+                } else {
+                    // FIXME #30159: This is required for backwards compatability.
+                    dest_import_resolution[namespace].is_public |= is_public;
                 }
             };
             merge_child_item(ValueNS);

src/test/compile-fail/shadowed-use-visibility.rs

@@ -17,10 +17,6 @@ pub fn f() {}
 
 mod bar {
     use foo::bar::f as g; //~ ERROR unresolved import
-
-    use foo as f;
-    pub use foo::*;
 }
 
-use bar::f::f; //~ ERROR unresolved import
 fn main() {}