patch 8.1.1378: delete() can not handle a file name that looks like a pattern

Problem:    Delete() can not handle a file name that looks like a pattern.
Solution:   Use readdir() instead of appending "/*" and expanding wildcards.
            (Ken Takata, closes #4424, closes #696)
diff --git a/src/proto/fileio.pro b/src/proto/fileio.pro
index 1844924..bff6640 100644
--- a/src/proto/fileio.pro
+++ b/src/proto/fileio.pro
@@ -24,6 +24,7 @@
 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 delete_recursive(char_u *name);
 void vim_deltempdir(void);
 char_u *vim_tempname(int extra_char, int keep);