Add test showing current behaviour

Author: kubawerlos

ext/tokenizer/tests/bug19507.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Bug #19507: Recursive tokenization during `token_get_all` result on error
+--EXTENSIONS--
+tokenizer
+--FILE--
+<?php
+
+set_error_handler(function (int $errno, string $msg) {
+    eval('123 + 2;');
+    echo 'error handler called: ', $msg, "\n";
+});
+
+
+$tokens = PhpToken::tokenize('<?php (double) $x;', TOKEN_PARSE);
+foreach ($tokens as $token) {
+    echo $token->getTokenName(), "\n";
+}
+
+--EXPECT--
+error handler called: Non-canonical cast (double) is deprecated, use the (float) cast instead
+T_OPEN_TAG
+T_LNUMBER
+;
+T_DOUBLE_CAST
+T_WHITESPACE
+T_VARIABLE
+;