Use nullptr instead of 0/NULL. (#1435)

* Use nullptr instead of 0/NULL.

* Update test-name-table.cc

src/hb-debug.hh

@@ -328,7 +328,7 @@ struct hb_auto_trace_t<0, ret_t>
 				   ...) HB_PRINTF_FUNC(6, 7) {}
 
   inline ret_t ret (ret_t v,
-		    const char *func HB_UNUSED = 0,
+		    const char *func HB_UNUSED = nullptr,
 		    unsigned int line HB_UNUSED = 0) { return v; }
 };
 

src/test-name-table.cc

@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#include "hb.h"
+#include "hb.hh"
 #include "hb-ot.h"
 
 #include <stdlib.h>
@@ -41,7 +41,7 @@ main (int argc, char **argv)
   hb_blob_t *blob = hb_blob_create_from_file (argv[1]);
   hb_face_t *face = hb_face_create (blob, 0 /* first face */);
   hb_blob_destroy (blob);
-  blob = NULL;
+  blob = nullptr;
 
   unsigned int count;
   const hb_ot_name_entry_t *entries = hb_ot_name_list_names (face, &count);