Removed #include of wingdi.h and windef.h from winuser.h (and resolved
the resulting compilation failures).

diff --git a/misc/system.c b/misc/system.c
index 9302671..dbb71a0 100644
--- a/misc/system.c
+++ b/misc/system.c
@@ -4,6 +4,8 @@
  * Copyright 1996 Alexandre Julliard
  */
 
+#include "windef.h"
+#include "wingdi.h"
 #include "wine/winbase16.h"
 #include "wine/winuser16.h"
 #include "services.h"