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

src/js/proxy.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();
 
 // ----------------------------------------------------------------------------
 // Imports
 //
 var GlobalProxy = global.Proxy;
 var GlobalFunction = global.Function;
 var GlobalObject = global.Object;
 var MakeTypeError;
 var ToNameArray;
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
   ToNameArray = from.ToNameArray;
 });
 
 //----------------------------------------------------------------------------
 
 function ProxyCreate(target, handler) {
-  if (!%_IsConstructCall()) {
+  if (IS_UNDEFINED(new.target)) {
     throw MakeTypeError(kConstructorNotFunction, "Proxy");
   }
   return %CreateJSProxy(target, handler);
 }
 
 function ProxyCreateFunction(handler, callTrap, constructTrap) {
   if (!IS_SPEC_OBJECT(handler))
     throw MakeTypeError(kProxyHandlerNonObject, "createFunction")
   if (!IS_CALLABLE(callTrap))
     throw MakeTypeError(kProxyTrapFunctionExpected, "call")
@@ skipping 20 matching lines @@
     var proto = this.prototype
     if (!IS_SPEC_OBJECT(proto)) proto = GlobalObject.prototype
     var obj = { __proto__: proto };
     var result = %Apply(callTrap, obj, arguments, 0, %_ArgumentsLength());
     return IS_SPEC_OBJECT(result) ? result : obj
   }
 }
 
 function DelegateCallAndConstruct(callTrap, constructTrap) {
   return function() {
-    return %Apply(%_IsConstructCall() ? constructTrap : callTrap,
+    return %Apply(IS_UNDEFINED(new.target) ? callTrap : constructTrap,
                   this, arguments, 0, %_ArgumentsLength())
   }
 }
 
 function DerivedGetTrap(receiver, name) {
   var desc = this.getPropertyDescriptor(name)
   if (IS_UNDEFINED(desc)) { return desc }
   if ('value' in desc) {
     return desc.value
   } else {
@@ skipping 117 matching lines @@
 });
 
 %InstallToContext([
   "derived_get_trap", DerivedGetTrap,
   "derived_has_trap", DerivedHasTrap,
   "derived_set_trap", DerivedSetTrap,
   "proxy_enumerate", ProxyEnumerate,
 ]);
 
 })