Re: Add 64-bit XIDs into PostgreSQL 15

Big thank you for your review. I've applied your addition in the recent patch set below.

Besides, mentioned above, next changes are made:

- rename HeapTupleCopyBaseFromPage to HeapTupleCopyXidsFromPage, since this old name came from the time when еру "t_xid_base" was stored in tuple,

  and not correspond to recent state of the code;

- replace ToastTupleHeader* calls with HeapHeader* with the "is_toast" argument. This reduces diff and make the code more readable;

- put HeapTupleSetZeroXids calls in several places for the sake of redundancy;

- in heap_tuple_would_freeze add case to reset xmax without reading clog;

- rename SeqTupleHeaderSetXmax/Xmin to SeqTupleSetXmax/min and refactoring of the function; Now it will set HeapTuple and HeapTupleHeader xmax;

- add case of int64 values in check_GUC_init;

- massive refactoring in htup_details.h to use inline functions with type control over macro;

- reorder code in htup_details.h to reduce overall diff.

As always, reviews and opinions are very welcome!