ag_check_sys_siglist

Check that the POSIX compliant regular expression compiler is available in the POSIX specified manner, and it works.

AC_DEFUN(AG_CHECK_SYS_SIGLIST,[
  AC_MSG_CHECKING([whether there is a global text array sys_siglist])
  AC_CACHE_VAL([ag_cv_sys_siglist],[
  AC_TRY_RUN([#include <signal.h>
int main() {
  const char* pz = sys_siglist[1];
  return (pz != 0) ? 0 : 1; }],[ag_cv_sys_siglist=yes],[ag_cv_sys_siglist=no],[ag_cv_sys_siglist=no]
           ) # end of TRY_RUN]) # end of CACHE_VAL

 AC_MSG_RESULT([$ag_cv_sys_siglist])
 if test x$ag_cv_sys_siglist = xyes
 then
   AC_DEFINE(HAVE_SYS_SIGLIST, 1,
      [Define this if there is a global text array sys_siglist])
 fi
 ]) # end of AC_DEFUN