alloc: Add tracking issue for rc_downcast

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 814be059da7c01d4ff32d1602e20ac54152131ca..58c589697f41c75127334a8e79d6604733ff0981 100644 (file)
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -611,7 +611,7 @@ pub fn make_mut(this: &mut Self) -> &mut T {
 
 impl Rc<Any> {
     #[inline]
-    #[unstable(feature = "rc_downcast", issue = "0")]
+    #[unstable(feature = "rc_downcast", issue = "44608")]
     /// Attempt to downcast the `Rc<Any>` to a concrete type.
     ///
     /// # Examples