Fix core dump reported by Pablo De Napoli in

<http://lists.gnu.org/archive/html/bug-bison/2005-07/msg00053.html>.
* tests/regression.at (Invalid inputs with {}): New test.
* src/parse-gram.y (token_name): Translate type before using
it as an index.

src/parse-gram.y

@@ -538,5 +538,5 @@ gram_error (location const *loc, char const *msg)
 char const *
 token_name (int type)
 {
-  return yytname[type];
+  return yytname[YYTRANSLATE (type)];
 }