Use new.target in favor of %_IsConstructCall intrinsic (1).

src/js/harmony-sharedarraybuffer.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.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 var GlobalSharedArrayBuffer = global.SharedArrayBuffer;
 var GlobalObject = global.Object;
 var MakeTypeError;
 var ToPositiveInteger;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
   ToPositiveInteger = from.ToPositiveInteger;
 })
 
 // -------------------------------------------------------------------
 
 function SharedArrayBufferConstructor(length) { // length = 1
-  if (%_IsConstructCall()) {
+  if (!IS_UNDEFINED(new.target)) {
     var byteLength = ToPositiveInteger(length, kInvalidArrayBufferLength);
     %ArrayBufferInitialize(this, byteLength, kShared);
   } else {
     throw MakeTypeError(kConstructorNotFunction, "SharedArrayBuffer");
   }
 }
 
 function SharedArrayBufferGetByteLen() {
   if (!IS_SHAREDARRAYBUFFER(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
@@ skipping 19 matching lines @@
     toStringTagSymbol, "SharedArrayBuffer", DONT_ENUM | READ_ONLY);
 
 utils.InstallGetter(GlobalSharedArrayBuffer.prototype, "byteLength",
                     SharedArrayBufferGetByteLen);
 
 utils.InstallFunctions(GlobalSharedArrayBuffer, DONT_ENUM, [
     "isView", SharedArrayBufferIsViewJS
 ]);
 
 })