Improve the CallSite constructor

src/js/messages.js

 // Copyright 2012 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) {
 
 %CheckIsBootstrapping();
 
@@ skipping 548 matching lines @@
 
 
 function GetStackTraceLine(recv, fun, pos, isGlobal) {
   return new CallSite(recv, fun, pos, false).toString();
 }
 
 // ----------------------------------------------------------------------------
 // Error implementation
 
 function CallSite(receiver, fun, pos, strict_mode) {
+  if (!IS_FUNCTION(fun)) {
+    throw MakeTypeError(kCallSiteExpectsFunction, typeof fun);
+  }
+
+  if (IS_UNDEFINED(new.target)) {
+    return new CallSite(receiver, fun, pos, strict_mode);
+  }
+
   SET_PRIVATE(this, callSiteReceiverSymbol, receiver);
   SET_PRIVATE(this, callSiteFunctionSymbol, fun);
-  SET_PRIVATE(this, callSitePositionSymbol, pos);
-  SET_PRIVATE(this, callSiteStrictSymbol, strict_mode);
+  SET_PRIVATE(this, callSitePositionSymbol, TO_INT32(pos));
+  SET_PRIVATE(this, callSiteStrictSymbol, TO_BOOLEAN(strict_mode));
 }
 
 function CallSiteGetThis() {
   return GET_PRIVATE(this, callSiteStrictSymbol)
       ? UNDEFINED : GET_PRIVATE(this, callSiteReceiverSymbol);
 }
 
 function CallSiteGetFunction() {
   return GET_PRIVATE(this, callSiteStrictSymbol)
       ? UNDEFINED : GET_PRIVATE(this, callSiteFunctionSymbol);
@@ skipping 416 matching lines @@
 utils.Export(function(to) {
   to.ErrorToString = ErrorToString;
   to.MakeError = MakeError;
   to.MakeRangeError = MakeRangeError;
   to.MakeSyntaxError = MakeSyntaxError;
   to.MakeTypeError = MakeTypeError;
   to.MakeURIError = MakeURIError;
 });
 
 });