Handle comparison between NaN and non-NaN values.

Thanks to @workingjubilee for spotting this.
(<#248 (comment)>)

jaq-json/src/lib.rs

@@ -891,13 +891,15 @@ fn float_cmp(left: f64, right: f64) -> Ordering {
     if left == 0. && right == 0. {
         // consider negative and positive 0 as equal
         Ordering::Equal
-    } else if left.is_nan() && right.is_nan() {
+    } else if left.is_nan() {
         // there are more than 50 shades of NaN, and which of these
         // you strike when you perform a calculation is not deterministic (!),
         // therefore `total_cmp` may yield different results for the same calculation
         // so we bite the bullet and handle this like in jq
         Ordering::Less
-    } else {
+    } else if right.is_nan() {
+        Ordering::Greater
+    } else
         f64::total_cmp(&left, &right)
     }
 }