8235514: Update record serialization tests to not use hard coded source versions

Reviewed-by: lancea

src/java.base/share/classes/java/lang/reflect/Modifier.java

@@ -46,8 +46,7 @@ public class Modifier {
     /**
      * Do not call.
      */
-    @Deprecated(forRemoval=true, since="14")
-    public Modifier() {}
+    private Modifier() {throw new AssertionError();}
 
 
     /**