Reverse equals arguments for overlock AtomicMap compatibility

Overlock's atomic map wraps map values with OneShotThunk and strips them on
retrieval. Unfortunately JCTool's NonBlockingHashMap performs an `.equals` call
in various methods, and this fails when the object is not a OneShotThunk as
their equals methods (correctly) say they are not equal to a
OneShotThunk. Reversing the order means the overriden .equals method in
OneShotThunk returns true if the argument is the same value or a OneShotThunk
wrapping the same value.

jctools-core/src/main/java/org/jctools/maps/NonBlockingHashMap.java

@@ -352,7 +352,7 @@ public boolean replace    ( TypeK  key, TypeV  oldValue, TypeV newValue ) {
     return objectsEquals(putIfMatch( key, newValue, oldValue ), oldValue);
   }
   private static boolean objectsEquals(Object a, Object b) {
-    return (a == b) || (a != null && a.equals(b));
+    return (a == b) || (b != null && b.equals(a));
   }
 
   // Atomically replace newVal for oldVal, returning the value that existed