tuple_data_split() lacked the type of the first argument, and
heap_page_item_attrs() has reversed the first and second argument,
with the bytea argument using an incorrect name.

Author: Laurenz Albe
Discussion: https://postgr.es/m/8f9ab7b16daf623e87eeef5203a4ffc0dece8dfd.camel@cybertec.at
Backpatch-through: 9.6