We need to have a way to list package routines.

Different implementation ways are possible.

Treat packages as SQL Standard Modules

We can add SQL Standard columns into INFORMATION_SCHEMA.ROUTINES:

• MODULE_SCHEMA
• MODULE_NAME
  and fill these new columns to:
• NULL for regular (schema) routines
• the schema and the name of the containing package for package routines

One will be able to run this statement to list routines in a specific package:

SELECT * FROM INFORMATION_SCHEMA.ROUTINES

WHERE MODULE_SCHEMA='package_db' AND MODULE_NAME='package_name';

Treat packages as separate instances (not modules)

This proposal assumes that a PACKAGE is something completely different from a MODULE.
Peter Gulutzan in his blog post at http://ocelot.ca/blog/blog/2024/01/31/packages-in-mariadb-default-mode/ suggest adding a special column PACKAGE_NAME into INFORMATION_SCHEMA.ROUTINES.

Implementation questions

No matter which presentation way we choose, listing package routines in INFORMATION_SCHEMA.ROUTINES can be inefficient in case if a database has many packages:
every CREATE PACKAGE BODY statement (and possibly every corresponding CREATE PACKAGE statement) will have to be parsed.