InnoDB page number mismatch by 0x100000

When testing the fix of MDEV-28371 using its RQG test case on a 32-bit executable, there turned out to be a different bug, reported in CMAKE_BUILD_TYPE=RelWIthDebInfo as follows:

2022-04-21 14:22:17 10 [ERROR] InnoDB: Space id and page no stored in the page, read in are [page id: space=4294967294, page number=73924], should be [page id: space=4294967294, page number=1122500]

2022-04-21 14:22:17 0xd9567ac0  InnoDB: Assertion failure in file /mariadb/10.9/storage/innobase/fsp/fsp0fsp.cc line 1589

The page number difference is exactly 1<<20, a constant that occurs in the function page_id_t::fold(). This failure is independent of the MDEV-28371 fix.

There is a debug assertion in mtr_t::page_lock() that also catches this:

  ut_ad(state < buf_page_t::UNFIXED ||

        page_id_t(page_get_space_id(block->page.frame),

                  page_get_page_no(block->page.frame)) == block->page.id());

The cause is not obvious to me. cmake -DWITH_UBSAN=ON is not reporting anything before the crash. The test does not fail on 64-bit platforms.