Remove runtime flags for sloppy mode block scoping features

test/mjsunit/es6/spread-call-new-class.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-sloppy
-
 
 (function testConstructClassStrict() {
   "use strict";
   class Base {
     constructor(...args) {
       this.baseArgs = args;
     }
     method() { return this.baseArgs; }
   }
 
@@ skipping 66 matching lines @@
   assertEquals([1, 2, 3], c.baseArgs);
   assertEquals([1, 2, 3], c.childArgs);
 
   c = new Child2(...[1, 2, 3]);
   assertInstanceof(c, Child2);
   assertInstanceof(c, Base);
   assertEquals(["extra", 1, 2, 3], c.method());
   assertEquals(["extra", 1, 2, 3], c.baseArgs);
   assertEquals([1, 2, 3], c.childArgs);
 })();