depending on <sys/wait.h> and WTERMSIG. Default to 64 instead
of 127, since 64 is the largest conceivable number for ancient
nonstandard hosts.
# define SIGNUM_BOUND (_sys_nsig - 1)
#elif defined NSIG
# define SIGNUM_BOUND (NSIG - 1)
# define SIGNUM_BOUND (_sys_nsig - 1)
#elif defined NSIG
# define SIGNUM_BOUND (NSIG - 1)
-#elif defined WTERMSIG
-# define SIGNUM_BOUND WTERMSIG (~ 0)
-# define SIGNUM_BOUND 127
+# define SIGNUM_BOUND 64