Simplify Tag struct
diff --git a/src/hb-open-file-private.hh b/src/hb-open-file-private.hh
index e72a098..ce5140f 100644
--- a/src/hb-open-file-private.hh
+++ b/src/hb-open-file-private.hh
@@ -84,7 +84,8 @@
   }
   inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
   {
-    const Tag t = tag;
+    Tag t;
+    t.set (tag);
     // TODO bsearch
     unsigned int count = numTables;
     for (unsigned int i = 0; i < count; i++)