Add Unicode 8.0 scripts

Based on https://bugzilla.mozilla.org/show_bug.cgi?id=1183209

src/hb-common.cc

@@ -493,6 +493,9 @@ hb_script_get_horizontal_direction (hb_script_t script)
     case HB_SCRIPT_PALMYRENE:
     case HB_SCRIPT_PSALTER_PAHLAVI:
 
+    /* Unicode-8.0 additions */
+    case HB_SCRIPT_OLD_HUNGARIAN:
+
       return HB_DIRECTION_RTL;
   }
 

src/hb-common.h

@@ -296,6 +296,13 @@ typedef enum
   /*7.0*/ HB_SCRIPT_TIRHUTA			= HB_TAG ('T','i','r','h'),
   /*7.0*/ HB_SCRIPT_WARANG_CITI			= HB_TAG ('W','a','r','a'),
 
+  /*8.0*/ HB_SCRIPT_AHOM                        = HB_TAG ('A','h','o','m'),
+  /*8.0*/ HB_SCRIPT_ANATOLIAN_HIEROGLYPHS       = HB_TAG ('H','l','u','w'),
+  /*8.0*/ HB_SCRIPT_HATRAN                      = HB_TAG ('H','a','t','r'),
+  /*8.0*/ HB_SCRIPT_MULTANI                     = HB_TAG ('M','u','l','t'),
+  /*8.0*/ HB_SCRIPT_OLD_HUNGARIAN               = HB_TAG ('H','u','n','g'),
+  /*8.0*/ HB_SCRIPT_SIGNWRITING                 = HB_TAG ('S','g','n','w'),
+
   /* No script set. */
   HB_SCRIPT_INVALID				= HB_TAG_NONE,