Merge branch '2.8' into 3.2

* 2.8:
  [DI] use assertStringEqualsFile when possible
  [VarDumper] Adapt to php 7.2 changes
  [Form][TwigBridge] Don't render _method in form_rest() for a child form
  [DoctrineBridge][PropertyInfo] Added support for Doctrine Embeddables
  [Validator] Fix IbanValidator for ukrainian IBANs

Author: nicolas-grekas

Tests/Dumper/PhpDumperTest.php

@@ -122,13 +122,13 @@ public function testAddService()
         // without compilation
         $container = include self::$fixturesPath.'/containers/container9.php';
         $dumper = new PhpDumper($container);
-        $this->assertEquals(str_replace('%path%', str_replace('\\', '\\\\', self::$fixturesPath.DIRECTORY_SEPARATOR.'includes'.DIRECTORY_SEPARATOR), file_get_contents(self::$fixturesPath.'/php/services9.php')), $dumper->dump(), '->dump() dumps services');
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/services9.php', str_replace(str_replace('\\', '\\\\', self::$fixturesPath.DIRECTORY_SEPARATOR.'includes'.DIRECTORY_SEPARATOR), '%path%', $dumper->dump()), '->dump() dumps services');
 
         // with compilation
         $container = include self::$fixturesPath.'/containers/container9.php';
         $container->compile();
         $dumper = new PhpDumper($container);
-        $this->assertEquals(str_replace('%path%', str_replace('\\', '\\\\', self::$fixturesPath.DIRECTORY_SEPARATOR.'includes'.DIRECTORY_SEPARATOR), file_get_contents(self::$fixturesPath.'/php/services9_compiled.php')), $dumper->dump(), '->dump() dumps services');
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/services9_compiled.php', str_replace(str_replace('\\', '\\\\', self::$fixturesPath.DIRECTORY_SEPARATOR.'includes'.DIRECTORY_SEPARATOR), '%path%', $dumper->dump()), '->dump() dumps services');
 
         $dumper = new PhpDumper($container = new ContainerBuilder());
         $container->register('foo', 'FooClass')->addArgument(new \stdClass());