add simple arguments test

modules/lang-painless/src/test/java/org/elasticsearch/painless/CastTests.java

@@ -162,6 +162,15 @@ public class CastTests extends ScriptTestCase {
         assertEquals(5, exec("def x = 5; return (int)x.longValue();"));
     }
     
+    /**
+     * Currently these do not adopt the argument value, we issue a separate cast!
+     */
+    public void testArgumentsDef() {
+        assertEquals(5, exec("def x = 5L; return (+(int)x);"));
+        assertEquals(6, exec("def x = 5; def y = 1L; return x + (int)y"));
+        assertEquals('b', exec("def x = 'abcdeg'; def y = 1L; x.charAt((int)y)"));
+    }
+    
     /**
      * Unary operators adopt the return value
      */