Do not use js builtins object when constructing an error.

src/messages.cc

Index: src/messages.cc
diff --git a/src/messages.cc b/src/messages.cc
index c7a44761a49a58a9d43ca2bdad640566f4e1b8a8..4e0c45f0f1992ca70ed191bfe63c6a4fac4bed7c 100644
--- a/src/messages.cc
+++ b/src/messages.cc
@@ -322,23 +322,29 @@ Handle<String> MessageTemplate::FormatMessage(Isolate* isolate,
 }
 
 
-MaybeHandle<String> MessageTemplate::FormatMessage(int template_index,
-                                                   Handle<String> arg0,
-                                                   Handle<String> arg1,
-                                                   Handle<String> arg2) {
-  Isolate* isolate = arg0->GetIsolate();
-  const char* template_string;
+const char* MessageTemplate::TemplateString(int template_index) {
   switch (template_index) {
-#define CASE(NAME, STRING)    \
-  case k##NAME:               \
-    template_string = STRING; \
-    break;
+#define CASE(NAME, STRING) \
+  case k##NAME:            \
+    return STRING;
     MESSAGE_TEMPLATES(CASE)
 #undef CASE
     case kLastMessage:
     default:
-      isolate->ThrowIllegalOperation();
-      return MaybeHandle<String>();
+      return NULL;
+  }
+}
+
+
+MaybeHandle<String> MessageTemplate::FormatMessage(int template_index,
+                                                   Handle<String> arg0,
+                                                   Handle<String> arg1,
+                                                   Handle<String> arg2) {
+  Isolate* isolate = arg0->GetIsolate();
+  const char* template_string = TemplateString(template_index);
+  if (template_string == NULL) {
+    isolate->ThrowIllegalOperation();
+    return MaybeHandle<String>();
   }
 
   IncrementalStringBuilder builder(isolate);