Author: Andreas Beckmann <anbe@debian.org>
Description: fix building with -Werror=implicit-function-declaration

--- a/troff/mbwc.h
+++ b/troff/mbwc.h
@@ -1,5 +1,7 @@
+#if 0
 #define mblen p9mblen
 #define mbtowc p9mbtowc
 #define mbstowcs p9mbstowcs
 #define wctomb p9wctomb
 #define wcstombs p9wcstombs
+#endif