https://bugs.gentoo.org/719512

Tiny definition copied from /usr/include/termios.h.
--- a/tty.c
+++ b/tty.c
@@ -57,6 +57,10 @@
 	size_t	 cursor;
 };
 
+#ifndef CCEQ
+#define CCEQ(val, c) ((c) == (val) && (val) != _POSIX_VDISABLE)
+#endif
+
 static void	tty_flush(struct tty *);
 static int	tty_getc(struct tty *);
 static int	tty_insert(struct tty *, int, int);