Fix support for PHP8 union types

Author: nicolas-grekas

ControllerMetadata/ArgumentMetadataFactory.php

@@ -45,7 +45,7 @@ public function createArgumentMetadata($controller): array
      */
     private function getType(\ReflectionParameter $parameter, \ReflectionFunctionAbstract $function): ?string
     {
-        if (!$type = $parameter->getType()) {
+        if (!($type = $parameter->getType()) instanceof \ReflectionNamedType) {
             return null;
         }
         $name = $type->getName();

EventListener/ErrorListener.php

@@ -99,7 +99,7 @@ public function onControllerArguments(ControllerArgumentsEvent $event)
         $r = new \ReflectionFunction(\Closure::fromCallable($event->getController()));
         $r = $r->getParameters()[$k] ?? null;
 
-        if ($r && (!$r->hasType() || \in_array($r->getType()->getName(), [FlattenException::class, LegacyFlattenException::class], true))) {
+        if ($r && (!($r = $r->getType()) instanceof \ReflectionNamedType || \in_array($r->getName(), [FlattenException::class, LegacyFlattenException::class], true))) {
             $arguments = $event->getArguments();
             $arguments[$k] = FlattenException::createFromThrowable($e);
             $event->setArguments($arguments);