[es6] Unify ArrayBuffer and SharedArrayBuffer constructors.

test/mjsunit/es6/classes-subclass-builtins.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: --allow-natives-syntax --harmony-reflect --harmony-regexp-subclass
 // Flags: --expose-gc
 
 "use strict";
 
 
@@ skipping 418 matching lines @@
   assertTrue(o instanceof ArrayBuffer);
   assertTrue(o instanceof A);
   assertEquals("object", typeof o);
   checkPrototypeChain(o, [A, ArrayBuffer, Object]);
 
   assertEquals(16, o.byteLength);
   assertEquals(42, o.a);
   assertEquals(4.2, o.d);
   assertEquals(153, o.o.foo);
 
-  var o1 = new A("bar");
+  var o1 = new A(8);
   assertTrue(%HaveSameMap(o, o1));
 
 
   class MyInt32Array extends Int32Array {
     constructor(v, name) {
       super(v);
       this.name = name;
     }
   }
 
@@ skipping 371 matching lines @@
 
   Object.defineProperty(pattern, Symbol.match, {
     get() { log.push("match"); f.prototype = p2; return false; }});
 
   var o = Reflect.construct(RegExp, [pattern], f);
   assertEquals(["match", "tostring"], log);
   assertEquals(/biep/, o);
   assertTrue(o.__proto__ === p2);
   assertTrue(f.prototype === p3);
 })();