Merge branch '3.4' into 4.3

* 3.4:
  Minor fixes
  Use namespaced Phpunit classes
  [Form] remove leftover int child phpdoc
  Support DateTimeInterface in IntlDateFormatter::format
  [PhpUnitBridge] fixed PHPUnit 8.3 compatibility: method handleError was renamed to __invoke
  Use PHPunit assertion

Author: nicolas-grekas

Tests/Compiler/ResolveInstanceofConditionalsPassTest.php

@@ -233,7 +233,7 @@ public function testProcessForAutoconfiguredCalls()
     public function testProcessThrowsExceptionForArguments()
     {
         $this->expectException('Symfony\Component\DependencyInjection\Exception\InvalidArgumentException');
-        $this->expectExceptionMessage('Autoconfigured instanceof for type "PHPUnit\Framework\TestCase" defines arguments but these are not supported and should be removed.');
+        $this->expectExceptionMessageRegExp('/Autoconfigured instanceof for type "PHPUnit[\\\\_]Framework[\\\\_]TestCase" defines arguments but these are not supported and should be removed\./');
         $container = new ContainerBuilder();
         $container->registerForAutoconfiguration(parent::class)
             ->addArgument('bar');

Tests/Config/ContainerParametersResourceCheckerTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\DependencyInjection\Tests\Config;
 
+use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\ResourceCheckerInterface;
 use Symfony\Component\DependencyInjection\Config\ContainerParametersResource;
@@ -52,15 +53,15 @@ public function testIsFresh(callable $mockContainer, $expected)
 
     public function isFreshProvider()
     {
-        yield 'not fresh on missing parameter' => [function (\PHPUnit\Framework\MockObject\MockObject $container) {
+        yield 'not fresh on missing parameter' => [function (MockObject $container) {
             $container->method('hasParameter')->with('locales')->willReturn(false);
         }, false];
 
-        yield 'not fresh on different value' => [function (\PHPUnit\Framework\MockObject\MockObject $container) {
+        yield 'not fresh on different value' => [function (MockObject $container) {
             $container->method('getParameter')->with('locales')->willReturn(['nl', 'es']);
         }, false];
 
-        yield 'fresh on every identical parameters' => [function (\PHPUnit\Framework\MockObject\MockObject $container) {
+        yield 'fresh on every identical parameters' => [function (MockObject $container) {
             $container->expects($this->exactly(2))->method('hasParameter')->willReturn(true);
             $container->expects($this->exactly(2))->method('getParameter')
                 ->withConsecutive(