Map more ISO 15924 variants to `hb_script_t`s

src/hb-common.cc

@@ -448,7 +448,12 @@ hb_script_from_iso15924_tag (hb_tag_t tag)
     case HB_TAG('Q','a','a','c'): return HB_SCRIPT_COPTIC;
 
     /* Script variants from https://unicode.org/iso15924/ */
+    case HB_TAG('A','r','a','n'): return HB_SCRIPT_ARABIC;
     case HB_TAG('C','y','r','s'): return HB_SCRIPT_CYRILLIC;
+    case HB_TAG('G','e','o','k'): return HB_SCRIPT_GEORGIAN;
+    case HB_TAG('H','a','n','s'): return HB_SCRIPT_HAN;
+    case HB_TAG('H','a','n','t'): return HB_SCRIPT_HAN;
+    case HB_TAG('J','a','m','o'): return HB_SCRIPT_HANGUL;
     case HB_TAG('L','a','t','f'): return HB_SCRIPT_LATIN;
     case HB_TAG('L','a','t','g'): return HB_SCRIPT_LATIN;
     case HB_TAG('S','y','r','e'): return HB_SCRIPT_SYRIAC;