Reland "[es6] Fix Function and GeneratorFunction built-ins subclassing."

src/js/v8natives.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();
 
 // ----------------------------------------------------------------------------
 // Imports
@@ skipping 1768 matching lines @@
   var body = (n > 0) ? TO_STRING(args[n - 1]) : '';
   return '(' + function_token + '(' + p + ') {\n' + body + '\n})';
 }
 
 
 function FunctionConstructor(arg1) {  // length == 1
   var source = NewFunctionString(arguments, 'function');
   var global_proxy = %GlobalProxy(FunctionConstructor);
   // Compile the string in the constructor and not a helper so that errors
   // appear to come from here.
-  var f = %_CallFunction(global_proxy, %CompileString(source, true));
-  %FunctionMarkNameShouldPrintAsAnonymous(f);
-  return f;
+  var func = %_CallFunction(global_proxy, %CompileString(source, true));
+  // Set name-should-print-as-anonymous flag on the ShareFunctionInfo and
+  // ensure that |func| uses correct initial map from |new.target| if
+  // it's available.
+  return %CompleteFunctionConstruction(func, GlobalFunction, new.target);
 }
 
 
 // ----------------------------------------------------------------------------
 
 %SetCode(GlobalFunction, FunctionConstructor);
 %AddNamedProperty(GlobalFunction.prototype, "constructor", GlobalFunction,
                   DONT_ENUM);
 
 utils.InstallFunctions(GlobalFunction.prototype, DONT_ENUM, [
@@ skipping 45 matching lines @@
 
 %InstallToContext([
   "global_eval_fun", GlobalEval,
   "object_value_of", ObjectValueOf,
   "object_to_string", ObjectToString,
   "object_get_own_property_descriptor", ObjectGetOwnPropertyDescriptor,
   "to_complete_property_descriptor", ToCompletePropertyDescriptor,
 ]);
 
 })