TreeCrash: prove lemmas about how [tree_crash] interacts with [find_subtree] and [update_subtree]
TreeCrash: prove lemmas about how [tree_crash] interacts with [find_subtree] and [update_subtree]

should be done with TreeCrash now

mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl