Add regression test for #117718

Author: GuillaumeGomez

tests/rustdoc-json/doc_hidden_reexports.rs

@@ -0,0 +1,19 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/117718>.
+// Ensures that the various "doc(hidden)" reexport cases are correctly handled.
+
+pub mod submodule {
+    #[doc(hidden)]
+    pub struct Hidden {}
+}
+
+#[doc(hidden)]
+mod x {
+    pub struct Y {}
+}
+
+// @has "$.index[*].inner[?(@.import.name=='UsedHidden')].import.source" '"submodule::Hidden"'
+// @has "$.index[*].inner[?(@.import.name=='UsedHidden')].import.id" "null"
+pub use submodule::Hidden as UsedHidden;
+// @has "$.index[*].inner[?(@.import.name=='Z')].import.source" '"x::Y"'
+// @has "$.index[*].inner[?(@.import.name=='Z')].import.id" 'null'
+pub use x::Y as Z;