Merge rust-bitcoin#4037: primitives: Add tests to LockTime

6cecc40 Test LockTime PartialOrd (Jamil Lambert, PhD)

Pull request description:

  Add tests to kill the mutants in both relative and absolute PartialOrd.

ACKs for top commit:
  tcharding:
    ACK 6cecc40
  apoelstra:
    ACK 6cecc40; successfully ran local tests; thanks!

Tree-SHA512: dba7d90e3f6e62f0d3417bacc09d38145dd29bf654f84c2d3bc68af30c0e65b105146466a384bd35ef4326913ca414fd31f92daa3d7ffe3ff409c49bd1c05d96

primitives/src/locktime/absolute.rs

@@ -501,6 +501,9 @@ mod tests {
         assert!(lock_by_height.is_satisfied_by(height_same, time));
         assert!(lock_by_height.is_satisfied_by(height_above, time));
         assert!(!lock_by_height.is_satisfied_by(height_below, time));
+
+        let lock_by_height_above = LockTime::from_consensus(800_000);
+        assert!(lock_by_height < lock_by_height_above)
     }
 
     #[test]
@@ -516,6 +519,9 @@ mod tests {
         assert!(lock_by_time.is_satisfied_by(height, time_same));
         assert!(lock_by_time.is_satisfied_by(height, time_after));
         assert!(!lock_by_time.is_satisfied_by(height, time_before));
+
+        let lock_by_time_after = LockTime::from_consensus(1653282000);
+        assert!(lock_by_time < lock_by_time_after);
     }
 
     #[test]

primitives/src/locktime/relative.rs

@@ -501,6 +501,9 @@ mod tests {
         assert!(!lock_by_height1.is_same_unit(lock_by_time1));
         assert!(lock_by_time1.is_same_unit(lock_by_time2));
         assert!(!lock_by_time1.is_same_unit(lock_by_height1));
+
+        assert!(lock_by_height1 < lock_by_height2);
+        assert!(lock_by_time1 < lock_by_time2);
     }
 
     #[test]