add tracking issue

Author: lcnr

library/core/src/array/mod.rs

@@ -20,14 +20,14 @@ mod iter;
 pub use iter::IntoIter;
 
 /// Converts a reference to `T` into a reference to an array of length 1 (without copying).
-#[unstable(feature = "array_from_ref", issue = "none")]
+#[unstable(feature = "array_from_ref", issue = "77101")]
 pub fn from_ref<T>(s: &T) -> &[T; 1] {
     // SAFETY: Converting `&T` to `&[T; 1]` is sound.
     unsafe { &*(s as *const T).cast::<[T; 1]>() }
 }
 
 /// Converts a mutable reference to `T` into a mutable reference to an array of length 1 (without copying).
-#[unstable(feature = "array_from_ref", issue = "none")]
+#[unstable(feature = "array_from_ref", issue = "77101")]
 pub fn from_mut<T>(s: &mut T) -> &mut [T; 1] {
     // SAFETY: Converting `&mut T` to `&mut [T; 1]` is sound.
     unsafe { &mut *(s as *mut T).cast::<[T; 1]>() }