Roll harfbuzz to pick up this/NULL comparison fix.

third_party/harfbuzz-ng/src/hb-set-private.hh

 /*
  * Copyright © 2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
@@ skipping 132 matching lines @@
 
 /* TODO Make this faster and memmory efficient. */
 
 struct hb_set_t
 {
   hb_object_header_t header;
   ASSERT_POD ();
   bool in_error;
 
   inline void init (void) {
-    header.init ();
+    hb_object_init (this);
     clear ();
   }
   inline void fini (void) {
   }
   inline void clear (void) {
     if (unlikely (hb_object_is_inert (this)))
       return;
     in_error = false;
     memset (elts, 0, sizeof elts);
   }
@@ skipping 167 matching lines @@
 
   elt_t elts[ELTS]; /* XXX 8kb */
 
   ASSERT_STATIC (sizeof (elt_t) * 8 == BITS);
   ASSERT_STATIC (sizeof (elt_t) * 8 * ELTS > MAX_G);
 };
 
 
 
 #endif /* HB_SET_PRIVATE_HH */