title: illegal instruction on exp_expectl with AIX 64 bit
body: <p>Please take a look at this simple utility program. It works fine with AIX when compiled to 32 bit using <code>libexpect5.42</code> provided by the operating system. 
  However, when linking with a 64 bit of libexpect which we manually compiled, we are getting an illegal instruction error on the call to <code>exp_expectl()</code>. Any ideas are welcomed.</p>
  
  <pre class="lang-c prettyprint-override"><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;expect.h&gt;
  #include &lt;errno.h&gt;
  #include &lt;string.h&gt;
  #include &lt;unistd.h&gt;
  
  
  int 
  main (int argc, char** argv, char** arge)
  {
    int returnValue = 0;
    int iFd = 0;
    int res = 0;
    exp_loguser = 1;
    exp_timeout = 5;
    exp_is_debugging = 0;
  
    printf("spawning process without argument\n");
    iFd = exp_spawnl ("ls", "ls",(char*)0  );
  
    printf ("spawned\n");
    printf ("iFd = %d\n", iFd);
  
    if (iFd &lt; 0)
    {
       printf ("Return %d\n",iFd);
    }
    else
    {
       res = exp_expectl (iFd, exp_glob,"ls", 0, exp_end);
       printf ("Return %d \n",res);
    }
    return iFd;
  }
  </code></pre>