Rename Option::cloned gate

Author: mbartlett21

library/core/src/option.rs

@@ -1497,7 +1497,7 @@ impl<T: Clone> Option<&T> {
     /// ```
     #[must_use = "`self` will be dropped if the result is not used"]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "option_const_cloned", issue = "none")]
+    #[rustc_const_unstable(feature = "const_option_cloned", issue = "none")]
     pub const fn cloned(self) -> Option<T> where T: ~const Clone {
         match self {
             Some(t) => Some(t.clone()),
@@ -1521,7 +1521,7 @@ impl<T: Clone> Option<&mut T> {
     /// ```
     #[must_use = "`self` will be dropped if the result is not used"]
     #[stable(since = "1.26.0", feature = "option_ref_mut_cloned")]
-    #[rustc_const_unstable(feature = "option_const_cloned", issue = "none")]
+    #[rustc_const_unstable(feature = "const_option_cloned", issue = "none")]
     pub const fn cloned(self) -> Option<T> where T: ~const Clone {
         match self {
             Some(t) => Some(t.clone()),