Fix bug in object literals with large array indexes as strings.

src/hashmap.h

Index: src/hashmap.h
diff --git a/src/hashmap.h b/src/hashmap.h
index 3b947beb5388673f9d2e7c6cfe6b226db807e351..27989889c3e665a6806a61557d6f6eb13f4b011e 100644
--- a/src/hashmap.h
+++ b/src/hashmap.h
@@ -49,7 +49,8 @@ class HashMap {
   typedef bool (*MatchFun) (void* key1, void* key2);
 
   // Dummy constructor.  This constructor doesn't set up the hash
-  // map properly so don't use it unless you have good reason.
+  // map properly so don't use it unless you have good reason (e.g.,
+  // you know that the HashMap will never be used).
   HashMap();
 
   // initial_capacity is the size of the initial hash map;