Remove --harmony-arrow-functions flag

test/mjsunit/strong/function-arity.js

 // Copyright 2015 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-arrow-functions --harmony-reflect
+// Flags: --strong-mode --harmony-reflect
 // Flags: --harmony-spread-calls --harmony-rest-parameters --allow-natives-syntax
 
 'use strict';
 
 
 function generateArguments(n, prefix) {
   let a = [];
   if (prefix) {
     a.push(prefix);
   }
@@ skipping 317 matching lines @@
           if (argumentCount < parameterCount) {
             assertThrows(code, TypeError);
           } else {
             assertDoesNotThrow(code);
           }
         }
       }
     }
   }
 })();