Fix build with Sun compiler
diff --git a/src/hb-blob.cc b/src/hb-blob.cc
index b6e696b..bbbc936 100644
--- a/src/hb-blob.cc
+++ b/src/hb-blob.cc
@@ -24,6 +24,9 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
+/* http://www.oracle.com/technetwork/articles/servers-storage-dev/standardheaderfiles-453865.html */
+#define _POSIX_C_SOURCE 3
+
 #include "hb-private.hh"
 
 #include "hb-blob.h"