[php] Ensure _runme.php calls check::done()

This function doesn't do anything currently so these missing calls are a
latent issue.  It could be used for e.g. memory leak checking in the
future though, and it's potentially a useful place to add code when
debugging.

Examples/test-suite/php/exception_order_runme.php

@@ -35,3 +35,5 @@ try {
 } catch (Exception $e) {
     check::equal($e->getMessage(), 'C++ E2 * exception thrown', '');
 }
+
+check::done();