Remove stale references to --harmony-arrays flag in mjsunit tests

test/mjsunit/es6/array-copywithin.js

Index: test/mjsunit/es6/array-copywithin.js
diff --git a/test/mjsunit/harmony/array-copywithin.js b/test/mjsunit/es6/array-copywithin.js
similarity index 99%
rename from test/mjsunit/harmony/array-copywithin.js
rename to test/mjsunit/es6/array-copywithin.js
index c3a0c14663bf29113d463577d565157ef0cdb415..ed52b7d5faa69cfd69be2431632e30688a37de70 100644
--- a/test/mjsunit/harmony/array-copywithin.js
+++ b/test/mjsunit/es6/array-copywithin.js
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-arrays
-
 (function copyWithinArity() {
   assertEquals(Array.prototype.copyWithin.length, 2);
 })();