add regression test

tests/ui/resolve/exported-macro-in-mod-147958.rs

@@ -0,0 +1,21 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/147958>
+
+//@ check-pass
+
+#![feature(decl_macro)]
+
+macro_rules! exported {
+    () => {
+        #[macro_export]
+        macro_rules! exported {
+            () => {};
+        }
+    };
+}
+use inner1::*;
+exported!();
+mod inner1 {
+    pub macro exported() {}
+}
+
+fn main() {}