+/* As we define BROKEN_FIONREAD, SIGIO will be undefined in systty.h.
+ But, on AIX, SIGAIO, SIGPTY, and SIGPOLL are defined as SIGIO,
+ which causes compilation error at init_signals in sysdep.c. So, we
+ define these macros so that syssignal.h detects them and undefine
+ SIGAIO, SIGPTY and SIGPOLL. */
+#define BROKEN_SIGAIO
+#define BROKEN_SIGPTY
+#define BROKEN_SIGPOLL