Rollup merge of rust-lang#71246 - crlf0710:linked_list_cursor, r=Amanieu

Implement `Clone` for `liballoc::collections::linked_list::Cursor`.

This implements `Clone` for linked list `Cursor`. Implementing `Copy` is also possible here, but i'm not sure whether i should also do it.

r? @Amanieu

Author: Dylan-DPC

src/liballoc/collections/linked_list.rs

@@ -1197,6 +1197,14 @@ pub struct Cursor<'a, T: 'a> {
     list: &'a LinkedList<T>,
 }
 
+#[unstable(feature = "linked_list_cursors", issue = "58533")]
+impl<T> Clone for Cursor<'_, T> {
+    fn clone(&self) -> Self {
+        let Cursor { index, current, list } = *self;
+        Cursor { index, current, list }
+    }
+}
+
 #[unstable(feature = "linked_list_cursors", issue = "58533")]
 impl<T: fmt::Debug> fmt::Debug for Cursor<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {