patch 8.2.0875: getting attributes for directory entries is slow

Problem:    Getting attributes for directory entries is slow.
Solution:   Add readdirex(). (Ken Takata, closes #5619)
diff --git a/src/proto/fileio.pro b/src/proto/fileio.pro
index c7b66ed..2171e6b 100644
--- a/src/proto/fileio.pro
+++ b/src/proto/fileio.pro
@@ -31,7 +31,7 @@
 void buf_reload(buf_T *buf, int orig_mode);
 void buf_store_time(buf_T *buf, stat_T *st, char_u *fname);
 void write_lnum_adjust(linenr_T offset);
-int readdir_core(garray_T *gap, char_u *path, void *context, int (*checkitem)(void *context, char_u *name));
+int readdir_core(garray_T *gap, char_u *path, int withattr, void *context, int (*checkitem)(void *context, void *item));
 int delete_recursive(char_u *name);
 void vim_deltempdir(void);
 char_u *vim_tempname(int extra_char, int keep);