xfuncs: Handle missing non-POSIX termios constants

Signed-off-by: James Clarke <jrtc27@jrtc27.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

libbb/xfuncs.c

@@ -355,6 +355,15 @@ int FAST_FUNC get_termios_and_make_raw(int fd, struct termios *newterm, struct t
 		 */
 	}
 	if (flags & TERMIOS_RAW_INPUT) {
+#ifndef IMAXBEL
+# define IMAXBEL 0
+#endif
+#ifndef IUCLC
+# define IUCLC 0
+#endif
+#ifndef IXANY
+# define IXANY 0
+#endif
 		/* IXOFF=0: disable sending XON/XOFF if input buf is full */
 		/* IXON=0: input XON/XOFF chars are not special */
 		/* dont convert anything on input */