Remove flags for spread calls and arrays

test/mjsunit/harmony/regress/regress-4417.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: --harmony-spread-arrays
-
-var arr = [1, 2, 3];
-assertEquals({arr: [1, 2, 3]}, {arr: [...arr]});
-assertEquals([[1, 2, 3]], [[...arr]]);
-
-assertEquals({arr: [6, 5, [1, 2, 3]]}, {arr: [6, 5, [...arr]]});
-assertEquals([8, 7, [6, 5, [1, 2, 3]]], [8, 7, [6, 5, [...arr]]]);