Fix warnings in rustdoc JS tests

Author: camelid

src/test/rustdoc-js/summaries.rs

@@ -1,6 +1,8 @@
 #![crate_type = "lib"]
 #![crate_name = "summaries"]
 
+#![allow(rustdoc::broken_intra_doc_links)]
+
 //! This *summary* has a [link], [`code`], and [`Sidebar2`] intra-doc.
 //!
 //! This is the second paragraph. It should not be rendered.