title: HHVM outputs status code 200 on fatal errors and I can't use fastcgi_next_upstream because of that
body: <p>I wanted to fallback to next upstream (php5-fpm) on nginx when HHVM fails. This isn't currently possible because HHVM outputs <code>200 OK</code> response code after fatal error. At least I wanted to give more informative status code.</p>
  
  <p>PHP Error-log:</p>
  
  <pre><code>\nFatal error: $this is null in /data/wordpress/htdocs/wp-content/plugins/woocommerce-gateway-klarna/classes/class-klarna-account.php on line 1231
  </code></pre>
  
  <p>And I know for sure that it works in php5-fpm.</p>
  
  <p>HHVM version:</p>
  
  <pre><code>hhvm --version
  HipHop VM 3.4.0 (rel)
  Compiler: tags/HHVM-3.4.0-0-g817b3a07fc4e509ce15635dbc87778e5b3496663
  Repo schema: 0e12aaa31fae66b5591f65603de50c9d62caafac
  Extension API: 20140829
  </code></pre>