[es6] new.target should not be shadowable in a with scope

test/mjsunit/harmony/new-target.js

Index: test/mjsunit/harmony/new-target.js
diff --git a/test/mjsunit/harmony/new-target.js b/test/mjsunit/harmony/new-target.js
index 9498099f50d13d9b26a8db8aa06710957201ee35..fa5b37282018d2615a83dc05cfff0f4738aefa38 100644
--- a/test/mjsunit/harmony/new-target.js
+++ b/test/mjsunit/harmony/new-target.js
@@ -381,4 +381,6 @@
   assertSame(f4, new f4);
   function f5() { 'use strict'; { let x; return new.target } }
   assertSame(f5, new f5);
+  function f6() { with ({'new.target': 42}) return new.target }
+  assertSame(f6, new f6);
 })();