add const hack comment

Author: fee1-dead

library/core/src/cmp.rs

@@ -802,6 +802,9 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
+        // HACK(fee1-dead): go back to using `self.max_by(other, Ord::cmp)`
+        // when trait methods are allowed to be used when a const closure is
+        // expected.
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => other,
             Ordering::Greater => self,
@@ -826,6 +829,9 @@ pub trait Ord: Eq + PartialOrd<Self> {
         Self: Sized,
         Self: ~const Destruct,
     {
+        // HACK(fee1-dead): go back to using `self.min_by(other, Ord::cmp)`
+        // when trait methods are allowed to be used when a const closure is
+        // expected.
         match self.cmp(&other) {
             Ordering::Less | Ordering::Equal => self,
             Ordering::Greater => other,