fix rustdoc and core test

library/core/tests/clone.rs

@@ -1,4 +1,5 @@
 #[test]
+#[cfg_attr(not(bootstrap), allow(suspicious_double_ref_op))]
 fn test_borrowed_clone() {
     let x = 5;
     let y: &i32 = &x;

src/librustdoc/html/format.rs

@@ -167,7 +167,7 @@ pub(crate) fn print_generic_bounds<'a, 'tcx: 'a>(
     display_fn(move |f| {
         let mut bounds_dup = FxHashSet::default();
 
-        for (i, bound) in bounds.iter().filter(|b| bounds_dup.insert(b.clone())).enumerate() {
+        for (i, bound) in bounds.iter().filter(|b| bounds_dup.insert(*b)).enumerate() {
             if i > 0 {
                 f.write_str(" + ")?;
             }