take the new DOM HTMLElement class into account

Author: xabbuh

src/Symfony/Component/VarDumper/Tests/Caster/DOMCasterTest.php

@@ -227,7 +227,7 @@ public function testCastModernElement()
         $attr = \Dom\HTMLDocument::createEmpty()->createElement('foo');
 
         $this->assertDumpMatchesFormat(<<<'EODUMP'
-            Dom\Element {%A
+            Dom\HTMLElement {%A
               +tagName: ? string
             %A}
             EODUMP,