Add regression test for GH-10570

Co-authored-by: Changochen <changochen1@gmail.com>

Author: nielsdos

Zend/tests/gh10570.phpt

@@ -0,0 +1,14 @@
+--TEST--
+GH-10570 (Assertion `(key)->h != 0 && "Hash must be known"' failed.): constant variation
+--FILE--
+<?php
+$a = new stdClass();
+for ($i = 0; $i < 2; $i++) {
+    $a->{90};
+    $a->{0} = 0;
+}
+?>
+--EXPECTF--
+Warning: Undefined property: stdClass::$90 in %s on line %d
+
+Warning: Undefined property: stdClass::$90 in %s on line %d