add regression test

Author: nikomatsakis

src/test/ui/issues/issue-56128.rs

@@ -0,0 +1,13 @@
+// Regression test for #56128. When this `pub(super) use...` gets
+// exploded in the HIR, we were not handling ids correctly.
+
+mod bar {
+    pub(super) use self::baz::{x, y};
+
+    mod baz {
+        pub fn x() { }
+        pub fn y() { }
+    }
+}
+
+fn main() { }