Add regression test for #107350

Author: GuillaumeGomez

tests/rustdoc/issue-107350.rs

@@ -0,0 +1,18 @@
+// This is a regression test for <https://github.com/rust-lang/rust/issues/107350>.
+// It shouldn't loop indefinitely.
+
+#![crate_name = "foo"]
+
+// @has 'foo/oops/enum.OhNo.html'
+
+pub mod oops {
+    pub use crate::oops::OhNo;
+
+    mod inner {
+        pub enum OhNo {
+            Item = 1,
+        }
+    }
+
+    pub use self::inner::*;
+}