[es6] Initial steps towards a correct implementation of IsCallable.

src/proxy.js

 // Copyright 2011 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();
 
@@ skipping 17 matching lines @@
   if (IS_UNDEFINED(proto))
     proto = null
   else if (!(IS_SPEC_OBJECT(proto) || IS_NULL(proto)))
     throw MakeTypeError(kProxyProtoNonObject)
   return %CreateJSProxy(handler, proto)
 }
 
 function ProxyCreateFunction(handler, callTrap, constructTrap) {
   if (!IS_SPEC_OBJECT(handler))
     throw MakeTypeError(kProxyHandlerNonObject, "createFunction")
-  if (!IS_SPEC_FUNCTION(callTrap))
+  if (!IS_CALLABLE(callTrap))
     throw MakeTypeError(kProxyTrapFunctionExpected, "call")
   if (IS_UNDEFINED(constructTrap)) {
     constructTrap = DerivedConstructTrap(callTrap)
-  } else if (IS_SPEC_FUNCTION(constructTrap)) {
+  } else if (IS_CALLABLE(constructTrap)) {
     // Make sure the trap receives 'undefined' as this.
     var construct = constructTrap
     constructTrap = function() {
       return %Apply(construct, UNDEFINED, arguments, 0, %_ArgumentsLength());
     }
   } else {
     throw MakeTypeError(kProxyTrapFunctionExpected, "construct")
   }
   return %CreateJSFunctionProxy(
     handler, callTrap, constructTrap, GlobalFunction.prototype)
@@ skipping 148 matching lines @@
 });
 
 %InstallToContext([
   "derived_get_trap", DerivedGetTrap,
   "derived_has_trap", DerivedHasTrap,
   "derived_set_trap", DerivedSetTrap,
   "proxy_enumerate", ProxyEnumerate,
 ]);
 
 })