rustdoc: add test case based on #103357

Author: notriddle

tests/rustdoc-js-std/regex.js

@@ -0,0 +1,10 @@
+// exact-check
+
+// https://github.com/rust-lang/rust/issues/103357
+const QUERY = 'regex';
+
+const EXPECTED = {
+    'others': [],
+    'in_args': [],
+    'returned': [],
+};