On the fsfs-format7 branch:  Make the "rev/item" part of a FSFS noderev ID
available as an ID part struct.  This is mainly for symmetry.  Replace
usages of svn_fs_fs__id_rev and svn_fs_fs__id_item with a single call to
svn_fs_fs__id_rev_item where appropriate.

This is part of the "numerical IDs" patch series.

* subversion/libsvn_fs_fs/id.h
  (svn_fs_fs__id_rev_item): declare new private API function
  (svn_fs_fs__id_rev_create): take rev and item as 1 ID part argument

* subversion/libsvn_fs_fs/id.c
  (fs_fs__id_t): store rev and item in an ID part struct
  (svn_fs_fs__id_rev_item): implement
  (svn_fs_fs__id_rev,
   svn_fs_fs__id_item,
   svn_fs_fs__id_unparse,
   svn_fs_fs__id_eq,
   svn_fs_fs__id_txn_create_root,
   svn_fs_fs__id_txn_create,
   svn_fs_fs__id_rev_create,
   svn_fs_fs__id_parse): update

* subversion/libsvn_fs_fs/cached_data.c
  (get_node_revision_body,
   svn_fs_fs__get_node_revision): use new rev_item ID part instead of
   making separate calls to *_rev() and *_item()

* subversion/libsvn_fs_fs/pack.c
  (compare_dir_entries_format6,
   copy_node_to_temp): ditto

* subversion/libsvn_fs_fs/recovery.c
  (recover_find_max_ids): same here

* subversion/libsvn_fs_fs/transaction.c
  (write_final_rev): adapt to interface change


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1454552 13f79535-47bb-0310-9956-ffa450edef68