From https://www.postgresql.org/docs/current/functions-info.html

The to_regclass, to_regproc, to_regprocedure, to_regoper, to_regoperator, and to_regtype functions translate relation, function, operator, and type names to objects of type regclass, regproc, regprocedure, regoper, regoperator, and regtype, respectively. These functions differ from a cast from text in that they don't accept a numeric OID, and that they return null rather than throwing an error if the name is not found (or, for to_regproc and to_regoper, if the given name matches multiple objects).

Jira issue: CRDB-13800