ReflectionUnionType in PHP 8

[kozaktomas]

Version: nette/di master, PHP 8

Bug Description

There is an issue with ReflectionUnionType in PHP 8. When a function uses union type for return && the function is used in config file => it doesn't work as expected because nette counts with ReflectionNamedType, but ReflectionUnionType is returned. Unfortunately ReflectionUnionType doesn't have getName() method

See screenshot with error and call stack:

Steps To Reproduce

Just create simple TestClass and put these lines to neon config

parameters:
    test: ::getenv("TEST") # reflection for getenv returns ReflectionUnionType

services:
	router: App\Router\RouterFactory::createRouter
	- App\Model\TestClass(%test%)

Possible Solution

1. Check for reflection type. BC break? ¯_(ツ)_/¯
2. Maybe it's PHP bug. But I couldn't find any bug report.