Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/dependency-injection/Compiler/RemoveAbstractDefinitionsPass.php

@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * Removes abstract Definitions.
+ */
+class RemoveAbstractDefinitionsPass implements CompilerPassInterface
+{
+    /**
+     * Removes abstract definitions from the ContainerBuilder.
+     *
+     * @param ContainerBuilder $container
+     */
+    public function process(ContainerBuilder $container)
+    {
+        $compiler = $container->getCompiler();
+        $formatter = $compiler->getLoggingFormatter();
+
+        foreach ($container->getDefinitions() as $id => $definition) {
+            if ($definition->isAbstract()) {
+                $container->removeDefinition($id);
+                $compiler->addLogMessage($formatter->formatRemoveService($this, $id, 'abstract'));
+            }
+        }
+    }
+}