I propose to remove the obsolete RECHECK keyword completely. This used
to be part of CREATE OPERATOR CLASS and ALTER OPERATOR FAMILY, but it
has done nothing (except issue a NOTICE) since PostgreSQL 8.4. Commit
30e7c175b81 removed support for dumping from pre-9.2 servers, so this no
longer serves any need, it seems to me.
This now removes it completely, and you'd get a normal parse error if
you used it.
