Merge branch 'bw/dir-c-stops-relying-on-the-index'

API update. * bw/dir-c-stops-relying-on-the-index: dir: convert fill_directory to take an index dir: convert read_directory to take an index dir: convert read_directory_recursive to take an index dir: convert open_cached_dir to take an index dir: convert is_excluded to take an index dir: convert prep_exclude to take an index dir: convert add_excludes to take an index dir: convert is_excluded_from_list to take an index dir: convert last_exclude_matching_from_list to take an index dir: convert dir_add* to take an index dir: convert get_dtype to take index dir: convert directory_exists_in_index to take index dir: convert read_skip_worktree_file_from_index to take an index dir: stop using the index compatibility macros