an #hb_script_t to convert.
an #hb_language_t to convert.
maximum number of script tags to retrieve (IN) and actual number of script tags retrieved (OUT)
array of size at least script_count to store the script tag results
maximum number of language tags to retrieve (IN) and actual number of language tags retrieved (OUT)
array of size at least language_count to store the language tag results
Converts an #hb_script_t and an #hb_language_t to script and language tags.