Add polyfill for PHP 8.1

Author: ondrejmirtes

compiler/build/scoper.inc.php

@@ -17,6 +17,7 @@
 	'../../vendor/jetbrains/phpstorm-stubs',
 	'../../vendor/phpstan/php-8-stubs/stubs',
 	'../../vendor/symfony/polyfill-php80',
+	'../../vendor/symfony/polyfill-php81',
 	'../../vendor/symfony/polyfill-mbstring',
 	'../../vendor/symfony/polyfill-intl-normalizer',
 	'../../vendor/symfony/polyfill-php73',
@@ -224,6 +225,7 @@ function (string $filePath, string $prefix, string $content): string {
 		'PhpParser',
 		'Hoa',
 		'Symfony\Polyfill\Php80',
+		'Symfony\Polyfill\Php81',
 		'Symfony\Polyfill\Mbstring',
 		'Symfony\Polyfill\Intl\Normalizer',
 		'Symfony\Polyfill\Php73',

composer.json

@@ -42,6 +42,7 @@
 		"symfony/polyfill-php73": "^1.23",
 		"symfony/polyfill-php74": "^1.23",
 		"symfony/polyfill-php80": "^1.23",
+		"symfony/polyfill-php81": "^1.27",
 		"symfony/process": "^5.4.3",
 		"symfony/service-contracts": "^2.5.0",
 		"symfony/string": "^5.4.3"

composer.lock

@@ -72,6 +72,7 @@ public function testExpectedFiles(): void
 			'symfony/polyfill-php73/bootstrap.php', // afaik polyfills aren't necessary
 			'symfony/polyfill-php74/bootstrap.php', // afaik polyfills aren't necessary
 			'symfony/polyfill-php80/bootstrap.php', // afaik polyfills aren't necessary
+			'symfony/polyfill-php81/bootstrap.php', // afaik polyfills aren't necessary
 			'symfony/string/Resources/functions.php', // afaik polyfills aren't necessary
 		];