Remove unused system table columns:

Remove unused system table columns:

pg_language.lancompiler
pg_operator.oprprec
pg_operator.oprisleft
pg_proc.proimplicit
pg_proc.probyte_pct
pg_proc.properbyte_cpu
pg_proc.propercall_cpu
pg_proc.prooutin_ratio
pg_shadow.usetrace
pg_type.typprtlen
pg_type.typreceive
pg_type.typsend

Attempts to use the obsoleted attributes of pg_operator or pg_proc
in the CREATE commands will be greeted by a warning.  For pg_type,
there is no warning (yet) because pg_dump scripts still contain these
attributes.

Also remove new but already obsolete spellings
isVolatile, isStable, isImmutable in WITH clause.  (Use new syntax
instead.)