[VarExporter] fix exporting classes with private constructors

src/Symfony/Component/VarExporter/Internal/Registry.php

@@ -65,14 +65,14 @@ class Registry
 
     public static function getClassReflector($class, $instantiableWithoutConstructor = false, $cloneable = null)
     {
-        if (!\class_exists($class) && !\interface_exists($class, false) && !\trait_exists($class, false)) {
+        if (!($isClass = \class_exists($class)) && !\interface_exists($class, false) && !\trait_exists($class, false)) {
             throw new ClassNotFoundException($class);
         }
         $reflector = new \ReflectionClass($class);
 
         if ($instantiableWithoutConstructor) {
             $proto = $reflector->newInstanceWithoutConstructor();
-        } elseif (!$reflector->isInstantiable()) {
+        } elseif (!$isClass || $reflector->isAbstract()) {
             throw new NotInstantiableTypeException($class);
         } elseif ($reflector->name !== $class) {
             $reflector = self::$reflectors[$name = $reflector->name] ?? self::getClassReflector($name, $instantiableWithoutConstructor, $cloneable);

src/Symfony/Component/VarExporter/Tests/Fixtures/private-constructor.php

@@ -0,0 +1,17 @@
+<?php
+
+return \Symfony\Component\VarExporter\Internal\Hydrator::hydrate(
+    $o = [
+        clone (\Symfony\Component\VarExporter\Internal\Registry::$prototypes['Symfony\\Component\\VarExporter\\Tests\\PrivateConstructor'] ?? \Symfony\Component\VarExporter\Internal\Registry::p('Symfony\\Component\\VarExporter\\Tests\\PrivateConstructor')),
+    ],
+    null,
+    [
+        'stdClass' => [
+            'prop' => [
+                'bar',
+            ],
+        ],
+    ],
+    $o[0],
+    []
+);

src/Symfony/Component/VarExporter/Tests/VarExporterTest.php

@@ -197,6 +197,8 @@ class VarExporterTest extends TestCase
         yield ['abstract-parent', new ConcreteClass()];
 
         yield ['foo-serializable', new FooSerializable('bar')];
+
+        yield ['private-constructor', PrivateConstructor::create('bar')];
     }
 }
 
@@ -250,6 +252,21 @@ class MyNotCloneable
     }
 }
 
+class PrivateConstructor
+{
+    public $prop;
+
+    public static function create($prop): self
+    {
+        return new self($prop);
+    }
+
+    private function __construct($prop)
+    {
+        $this->prop = $prop;
+    }
+}
+
 class MyPrivateValue
 {
     protected $prot;