adsrc and consrc incompatible with rename operations

The system catalog columns pg_attrdef.adsrc and pg_constraint.consrc store
"human-readable" versions of pg_attrdef.adbin and pg_constraint.conbin.
During a rename operation, they are not and cannot be updated.  We need to
remove them and make interested applications get the information about of
the *bin columns.  I noticed that various functions were recently updated
to do that, but I think the columns should be removed altogether because
they cannot be trusted.

-- 
Peter Eisentraut   peter_e@gmx.net