Use instance type in Object::IsErrorObject().

src/messages.cc

Index: src/messages.cc
diff --git a/src/messages.cc b/src/messages.cc
index d5a15256b9fa0cfd75b5fda18aaa972dc15d47bf..e6ab0afcc1198860aa405866e50310c376a8b647 100644
--- a/src/messages.cc
+++ b/src/messages.cc
@@ -98,7 +98,7 @@ void MessageHandler::ReportMessage(Isolate* isolate, MessageLocation* loc,
     MaybeHandle<Object> maybe_stringified;
     Handle<Object> stringified;
     // Make sure we don't leak uncaught internally generated Error objects.
-    if (Object::IsErrorObject(isolate, argument)) {
+    if (Object::IsErrorObject(argument)) {
       Handle<Object> args[] = {argument};
       maybe_stringified = Execution::TryCall(
           isolate, isolate->no_side_effects_to_string_fun(),