updated for version 7.3.177
Problem: MS-Windows: mkdir() doesn't work properly when 'encoding' is
"utf-8".
Solution: Convert to utf-16. (Yukihiro Nakadaira)
diff --git a/src/proto/os_win32.pro b/src/proto/os_win32.pro
index a3f5b3e..68d4ee2 100644
--- a/src/proto/os_win32.pro
+++ b/src/proto/os_win32.pro
@@ -20,6 +20,7 @@
int mch_setperm __ARGS((char_u *name, long perm));
void mch_hide __ARGS((char_u *name));
int mch_isdir __ARGS((char_u *name));
+int mch_mkdir __ARGS((char_u *name));
int mch_is_linked __ARGS((char_u *fname));
int win32_fileinfo __ARGS((char_u *name, BY_HANDLE_FILE_INFORMATION *lpFileInfo));
int mch_writable __ARGS((char_u *name));