Add testcase on V8Js::createSnapshot

tests/create_snapshot_basic.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Test V8Js::createSnapshot() : Basic snapshot creation & re-use
+--SKIPIF--
+<?php
+require_once(dirname(__FILE__) . '/skipif.inc');
+
+if (!method_exists('V8Js', 'createSnapshot')) {
+    die('SKIP V8Js::createSnapshot not supported');
+}
+?>
+--FILE--
+<?php
+$doublifySource = <<<EOJS
+function doublify(x) {
+    return 2 * x;
+}
+EOJS;
+
+$snap = V8Js::createSnapshot($doublifySource);
+
+if (strlen($snap) > 0) {
+    var_dump("snapshot successfully created");
+}
+
+$v8 = new V8Js('PHP', array(), array(), true, $snap);
+$v8->executeString('var_dump(doublify(23));');
+?>
+===EOF===
+--EXPECT--
+string(29) "snapshot successfully created"
+int(46)
+===EOF===