and do not call ibuf_merge_or_delete_for_page() in crash recovery,
before the redo log has been applied.
This could cure some hard-to-repeat, hard-to-explain bugs
related to secondary indexes.

A possible recipe to repeat the bug:

1. update a secondary index leaf page on a compressed table
2. evict the page from the buffer pool while it is still dirty
3. ibuf_insert() something for the page
4. crash
5. crash recovery; ibuf merge would be done too early,
before applying redo log to the sec index page or the ibuf pages