InnoDB acquires an x-latch on btr_search_latch for certain in-place updates
that do affect the adaptive hash index. These operations do not really need
to be protected by the btr_search_latch:

* updating DB_TRX_ID
* updating DB_ROLL_PTR
* updating PAGE_MAX_TRX_ID
* updating the delete-mark flag

rb:750 approved by Sunny Bains