Move provariadic sanity check to a more appropriate place
35f059e9bdfb3b14ac9d22a9e159d36ec0ccf804 put the provariadic sanity
check into type_sanity.sql, even though it's not about types, and
moreover in the middle of some connected test group, which makes it
all very confusing. Move it to opr_sanity.sql, where it is in better
company.