Reverse-convert row types in ExecWithCheckOptions.
Just as we already do in ExecConstraints, and for the same reason:
to improve the quality of error messages.
Etsuro Fujita, reviewed by Amit Langote
Discussion: http://postgr.es/m/
56e0baa8-e458-2bbb-7936-
367f7d832e43@lab.ntt.co.jp