Mark leading_trailing_ones with tracking issue 57969

Author: Thom Chiovoloni

src/libcore/num/mod.rs

@@ -407,7 +407,7 @@ let n = -1", stringify!($SelfT), ";
 assert_eq!(n.leading_ones(), ", stringify!($BITS), ");",
 $EndFeature, "
 ```"),
-            #[unstable(feature = "leading_trailing_ones", reason = "newly added", issue = "0")]
+            #[unstable(feature = "leading_trailing_ones", issue = "57969")]
             #[inline]
             pub const fn leading_ones(self) -> u32 {
                 (self as $UnsignedT).leading_ones()
@@ -428,7 +428,7 @@ let n = 3", stringify!($SelfT), ";
 assert_eq!(n.trailing_ones(), 2);",
 $EndFeature, "
 ```"),
-            #[unstable(feature = "leading_trailing_ones", reason = "newly added", issue = "0")]
+            #[unstable(feature = "leading_trailing_ones", issue = "57969")]
             #[inline]
             pub const fn trailing_ones(self) -> u32 {
                 (self as $UnsignedT).trailing_ones()
@@ -2540,7 +2540,7 @@ let n = !(", stringify!($SelfT), "::max_value() >> 2);
 
 assert_eq!(n.leading_ones(), 2);", $EndFeature, "
 ```"),
-            #[unstable(feature = "leading_trailing_ones", reason = "newly added", issue = "0")]
+            #[unstable(feature = "leading_trailing_ones", issue = "57969")]
             #[inline]
             pub const fn leading_ones(self) -> u32 {
                 (!self).leading_zeros()
@@ -2561,7 +2561,7 @@ let n = 0b1010111", stringify!($SelfT), ";
 
 assert_eq!(n.trailing_ones(), 3);", $EndFeature, "
 ```"),
-            #[unstable(feature = "leading_trailing_ones", reason = "newly added", issue = "0")]
+            #[unstable(feature = "leading_trailing_ones", issue = "57969")]
             #[inline]
             pub const fn trailing_ones(self) -> u32 {
                 (!self).trailing_zeros()