document that ptr cmp is unsigned

Author: hkBst

library/core/src/ptr/const_ptr.rs

@@ -1694,7 +1694,7 @@ impl<T: ?Sized> PartialEq for *const T {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Eq for *const T {}
 
-// Comparison for pointers
+/// Pointers are compared as if they are usize
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Ord for *const T {
     #[inline]