Fix: AstValueFactory must be internalized before ThrowPendingError.

src/ast-value-factory.h

Index: src/ast-value-factory.h
diff --git a/src/ast-value-factory.h b/src/ast-value-factory.h
index 59efa58c51012a05552b0ab829997aad268cf661..7749b5cf335f0f0394c91acebe30826e14802bdd 100644
--- a/src/ast-value-factory.h
+++ b/src/ast-value-factory.h
@@ -248,6 +248,9 @@ class AstValueFactory {
   const AstString* GetString(Handle<String> literal);
 
   void Internalize(Isolate* isolate);
+  bool IsInternalized() {
+    return isolate_ != NULL;
+  }
 
 #define F(name, str) \
   const AstString* name##_string() const { return name##_string_; }