BUG #16942: Misleading error message on denied permission for column in table

The following bug has been logged on the website:

Bug reference:      16942
Logged by:          Mihail Gershkovich
Email address:      mihail.gershkovich@gmail.com
PostgreSQL version: 13.0
Operating system:   OpenSUSE
Description:

-- reproduce:

CREATE ROLE table_writer; CREATE ROLE table_reader; CREATE ROLE
table_processor;
GRANT column_reader TO column_writer;

CREATE TABLE column_access_test (open1 varchar, open2 varchar, closed1
varchar);

GRANT SELECT(open1,open2,closed1) ON column_access_test  TO
table_processor;
GRANT INSERT(open1,open2, closed1 ), UPDATE(open1,open2, closed1 ) ON
column_access_test TO column_writer;
GRANT SELECT(open1,open2) ON column_access_test  TO column_reader ;

SET ROLE column_reader;
SELECT open1, open2 from column_access_test; -- works fine
SELECT open1, open2, closed1 from column_access_test; -- access is
prohibited, as expected, but error message is misleading

/*
Error:
SQL Error [42501]: ERROR: permission denied for table XYZ
should be something like: ERROR: permission denied for column A in table B
makes troubleshooting of permissions cumbersome.
*/