Fix crash during error reporting during bootstrapping.

src/factory.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 383 matching lines @@
 Handle<Object> Factory::NewError(const char* type,
                                  Vector< Handle<Object> > args) {
   return NewError("MakeError", type, args);
 }
 
 
 Handle<Object> Factory::NewError(const char* maker,
                                  const char* type,
                                  Handle<JSArray> args) {
   Handle<String> make_str = Factory::LookupAsciiSymbol(maker);
-  Handle<JSFunction> fun =
-      Handle<JSFunction>(
-          JSFunction::cast(
-              Top::builtins()->GetProperty(*make_str)));
+  Handle<Object> fun_obj(Top::builtins()->GetProperty(*make_str));
+  // If the builtins haven't been properly configured yet this error
+  // constructor may not have been defined.  Bail out.
+  if (!fun_obj->IsJSFunction())
+    return Factory::undefined_value();
+  Handle<JSFunction> fun = Handle<JSFunction>::cast(fun_obj);
   Handle<Object> type_obj = Factory::LookupAsciiSymbol(type);
   Object** argv[2] = { type_obj.location(),
                        Handle<Object>::cast(args).location() };
 
   // Invoke the JavaScript factory method. If an exception is thrown while
   // running the factory method, use the exception as the result.
   bool caught_exception;
   Handle<Object> result = Execution::TryCall(fun,
                                              Top::builtins(),
                                              2,
@@ skipping 509 matching lines @@
     Execution::ConfigureInstance(instance,
                                  instance_template,
                                  pending_exception);
   } else {
     *pending_exception = false;
   }
 }
 
 
 } }  // namespace v8::internal