Merge branch '2.3' into 2.4

* 2.3:
  changed some PHPUnit assertions to more specific ones
  fixed Kernel::stripComments() normalizing new-lines
  added a BC comment
  Update FileLoader to fix issue #10339

Author: fabpot

Tests/CacheWarmer/TemplateFinderTest.php

@@ -46,7 +46,7 @@ function ($template) { return $template->getLogicalName(); },
             $finder->findAllTemplates()
         );
 
-        $this->assertEquals(6, count($templates), '->findAllTemplates() find all templates in the bundles and global folders');
+        $this->assertCount(6, $templates, '->findAllTemplates() find all templates in the bundles and global folders');
         $this->assertContains('BaseBundle::base.format.engine', $templates);
         $this->assertContains('BaseBundle::this.is.a.template.format.engine', $templates);
         $this->assertContains('BaseBundle:controller:base.format.engine', $templates);