Revert of Array length reduction should throw in strict mode if it can't delete an element.

test/mjsunit/regress/regress-4267.js

-// Copyright 2016 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: --allow-natives-syntax
-
-"use strict";
-
-var a = [];
-Object.defineProperty(a, "0", {configurable: false, value: 10});
-assertEquals(1, a.length);
-var setter = ()=>{ a.length = 0; };
-assertThrows(setter);
-assertThrows(setter);
-%OptimizeFunctionOnNextCall(setter);
-assertThrows(setter);