Avoid triggering the autoloader in Deprecation::isLegacy()

Signed-off-by: Alexander M. Turek <me@derrabus.de>

Author: derrabus

DeprecationErrorHandler/Deprecation.php

@@ -20,6 +20,8 @@
 use Symfony\Component\Debug\DebugClassLoader as LegacyDebugClassLoader;
 use Symfony\Component\ErrorHandler\DebugClassLoader;
 
+class_exists(Groups::class);
+
 /**
  * @internal
  */
@@ -194,7 +196,7 @@ public function isLegacy()
         }
 
         $method = $this->originatingMethod();
-        $groups = class_exists(Groups::class) ? [new Groups(), 'groups'] : [Test::class, 'getGroups'];
+        $groups = class_exists(Groups::class, false) ? [new Groups(), 'groups'] : [Test::class, 'getGroups'];
 
         return 0 === strpos($method, 'testLegacy')
             || 0 === strpos($method, 'provideLegacy')