privilages system table in postgres
I don't think there is a canned view for that purpose, but such a query is possible to write.

You'd have to query each object type independently, forming a big UNION. A number of system information functions are available for checking permissions on objects, see the Access Privilege Inquiry Functions table.

Combine them with queries over information_schema, or over the internal PostgreSQL tables like pg_class, pg_proc, etc, and you'll be able to collect the desired information.

You might find the queries psql uses to implement \dp and the various + commands like \df+ informative. Run psql with -E to see them.