Re: Add 64-bit XIDs into PostgreSQL 15

Re: clog page numbers, as returned by TransactionIdToPage

- int pageno = TransactionIdToPage(xid); /* get page of parent */
+ int64 pageno = TransactionIdToPage(xid); /* get page of parent */

...

- int pageno = TransactionIdToPage(subxids[0]);
+ int64 pageno = TransactionIdToPage(subxids[0]);
int offset = 0;
int i = 0;

...

- int nextpageno;
+ int64 nextpageno;

Etc.

In all those places where you are replacing int with int64 for the kind of values returned by TransactionIdToPage(), would you mind replacing the int64's with a type name, such as ClogPageNumber, for improved code maintainability?