Because the CURRENT_DATABASE can not only being used on COMMENT ON statement but also on other statements as following list so the patch name is renamed to "support_CURRENT_DATABASE_keyword_vxx.patch".
1. COMMENT ON DATABASE CURRENT_DATABASE is ...
2. ALTER DATABASE CURRENT_DATABASE OWNER to ...
3. ALTER DATABASE CURRENT_DATABASE SET parameter ...
4. ALTER DATABASE CURRENT_DATABASE RESET parameter ...
5. ALTER DATABASE CURRENT_DATABASE RESET ALL
6. SELECT CURRENT_DATABASE
7. SECURITY LABEL ON DATABASE CURRENT_DATABASE
8. ALTER ROLE ... IN DATABASE CURRENT_DATABASE SET/RESET configuration_parameter
9. GRANT ... ON DATABASE CURRENT_DATABASE TO role_specification ...
10. REVOKE ... ON DATABASE CURRENT_DATABASE FROM ...