bpo-34412: Make signal.strsignal() work on HP-UX (GH-8786)

Introduce a configure check for strsignal(3) which defines HAVE_STRSIGNAL for
signalmodule.c. Add some common signals on HP-UX. This change applies for
Windows and HP-UX.
diff --git a/configure b/configure
index 87f3392..4de6843 100755
--- a/configure
+++ b/configure
@@ -11256,7 +11256,7 @@
  sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \
  sched_rr_get_interval \
  sigaction sigaltstack sigfillset siginterrupt sigpending sigrelse \
- sigtimedwait sigwait sigwaitinfo snprintf strftime strlcpy symlinkat sync \
+ sigtimedwait sigwait sigwaitinfo snprintf strftime strlcpy strsignal symlinkat sync \
  sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
  truncate uname unlinkat unsetenv utimensat utimes waitid waitpid wait3 wait4 \
  wcscoll wcsftime wcsxfrm wmemcmp writev _getpty