updated for version 7.4.393
Problem:    Text drawing on newer MS-Windows systems is suboptimal.  Some
            multi-byte characters are not displayed, even though the same font
            in Notepad can display them. (Srinath Avadhanula)
Solution:   Add the 'renderoptions' option to enable Direct-X drawing. (Taro
            Muraoka)
diff --git a/src/proto/gui_w32.pro b/src/proto/gui_w32.pro
index a333233..88fbf67 100644
--- a/src/proto/gui_w32.pro
+++ b/src/proto/gui_w32.pro
@@ -1,4 +1,6 @@
 /* gui_w32.c */
+int directx_enabled __ARGS((void));
+int gui_mch_set_rendering_options __ARGS((char_u *s));
 void gui_mch_set_blinking __ARGS((long wait, long on, long off));
 void gui_mch_stop_blink __ARGS((void));
 void gui_mch_start_blink __ARGS((void));