Remove --harmony-arrow-functions flag

test/mjsunit/strong/undefined.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --strong-mode --harmony-sloppy --harmony-arrow-functions
+// Flags: --strong-mode --harmony-sloppy
 
 // Repurposing the strict mode 'eval' and 'arguments' tests to test for correct
 // behaviour of 'undefined' as an identifier in strong mode.
 "use strict";
 
 function CheckStrongMode(code) {
   let strictContexts = [
     ["'use strict';", ""],
     ["function outer() { 'use strict';", "}"],
     ["function outer() { 'use strict'; function inner() {", "}}"],
@@ skipping 175 matching lines @@
 assertThrows("(undefined => {'use strong';});");
 
 CheckStrongMode("((undefined, b, c) => {return});");
 assertThrows("((undefined, b, c) => {'use strong';});");
 
 CheckStrongMode("((a, undefined, c) => {return});");
 assertThrows("((a, undefined, c) => {'use strong';});");
 
 CheckStrongMode("((a, b, undefined) => {return});");
 assertThrows("((a, b, undefined) => {'use strong';});");