Replace warning by isolated test

Author: jderusse

Tests/Resource/ClassExistenceResourceTest.php

@@ -12,7 +12,6 @@
 namespace Symfony\Component\Config\Tests\Resource;
 
 use PHPUnit\Framework\TestCase;
-use PHPUnit\Framework\Warning;
 use Symfony\Component\Config\Resource\ClassExistenceResource;
 use Symfony\Component\Config\Tests\Fixtures\BadParent;
 use Symfony\Component\Config\Tests\Fixtures\Resource\ConditionalClass;
@@ -76,23 +75,22 @@ public function testExistsKo()
         }
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testBadParentWithTimestamp()
     {
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
-
         $res = new ClassExistenceResource(BadParent::class, false);
         $this->assertTrue($res->isFresh(time()));
     }
 
+    /**
+     * @runInSeparateProcess https://github.com/symfony/symfony/issues/32995
+     */
     public function testBadParentWithNoTimestamp()
     {
         $this->expectException('ReflectionException');
         $this->expectExceptionMessage('Class Symfony\Component\Config\Tests\Fixtures\MissingParent not found');
-        if (\PHP_VERSION_ID >= 70400) {
-            throw new Warning('PHP 7.4 breaks this test, see https://bugs.php.net/78351.');
-        }
 
         $res = new ClassExistenceResource(BadParent::class, false);
         $res->isFresh(0);