Add test

Author: nikic

ext/tokenizer/tests/PhpToken_toString.phpt

@@ -0,0 +1,18 @@
+--TEST--
+PhpToken implements __toString()
+--FILE--
+<?php
+
+$tokens = PhpToken::getAll('<?php echo "Hello ". $what;');
+var_dump(implode($tokens));
+
+var_dump($tokens[0] instanceof Stringable);
+var_dump((string) $tokens[0]);
+var_dump($tokens[0]->__toString());
+
+?>
+--EXPECT--
+string(27) "<?php echo "Hello ". $what;"
+bool(true)
+string(6) "<?php "
+string(6) "<?php "