When we can do fast truncates of whole pages, we create a structure called WT_PAGE_DELETED that is attached to the page. This structure serves a similar purpose to WT_UPDATE: it has an associated transaction ID (and now timestamp), and has to be updated during transaction commit and rollback.

Now that we have explicit support for multiple types of WT_UPDATE's, we should be able to make use one directly to mark pages deleted, and do away with the special case transaction code for WT_PAGE_DELETED.