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

vendor/doctrine/instantiator/composer.json

@@ -0,0 +1,45 @@
+{
+    "name":              "doctrine/instantiator",
+    "description":       "A small, lightweight utility to instantiate objects in PHP without invoking their constructors",
+    "type":              "library",
+    "license":           "MIT",
+    "homepage":          "https://github.com/doctrine/instantiator",
+    "keywords":          [
+        "instantiate",
+        "constructor"
+    ],
+    "authors": [
+        {
+            "name":     "Marco Pivetta",
+            "email":    "ocramius@gmail.com",
+            "homepage": "http://ocramius.github.com/"
+        }
+    ],
+    "require": {
+        "php": ">=5.3,<8.0-DEV"
+    },
+    "require-dev": {
+        "ext-phar":                  "*",
+        "ext-pdo":                   "*",
+        "phpunit/phpunit":           "~4.0",
+        "squizlabs/php_codesniffer": "~2.0",
+        "athletic/athletic":         "~0.1.8"
+    },
+    "autoload": {
+        "psr-4": {
+            "Doctrine\\Instantiator\\": "src/Doctrine/Instantiator/"
+        }
+    },
+    "autoload-dev": {
+        "psr-0": {
+            "DoctrineTest\\InstantiatorPerformance\\": "tests",
+            "DoctrineTest\\InstantiatorTest\\": "tests",
+            "DoctrineTest\\InstantiatorTestAsset\\": "tests"
+        }
+    },
+    "extra": {
+        "branch-alias": {
+            "dev-master": "1.0.x-dev"
+        }
+    }
+}