Fix crash in gengtype debug dump

gcc/
	PR other/65800
	* gengtype.c (dump_type): Handle TYPE_UNDEFINED correctly.

From-SVN: r228956

gcc/ChangeLog

+2015-10-18  Mikhail Maltsev  <maltsevm@gmail.com>
+
+	PR other/65800
+	* gengtype.c (dump_type): Handle TYPE_UNDEFINED correctly.
+
 2015-10-18  Iain Sandoe  <iain@codesourcery.com>
 
 	* config/darwin.h (TARGET_SYSTEM_ROOT): Remove this from here,

gcc/gengtype.c

@@ -4878,10 +4878,17 @@ dump_type (int indent, type_p t)
 {
   PTR *slot;
 
+  printf ("%*cType at %p: ", indent, ' ', (void *) t);
+  if (t->kind == TYPE_UNDEFINED)
+    {
+      gcc_assert (t->gc_used == GC_UNUSED);
+      printf ("undefined.\n");
+      return;
+    }
+
   if (seen_types == NULL)
     seen_types = htab_create (100, htab_hash_pointer, htab_eq_pointer, NULL);
 
-  printf ("%*cType at %p: ", indent, ' ', (void *) t);
   slot = htab_find_slot (seen_types, t, INSERT);
   if (*slot != NULL)
     {