minor symfony#42083 Use PHP_OS_FAMILY if possible (javiereguiluz)

This PR was submitted for the 5.4 branch but it was merged into the 5.2 branch instead.

Discussion
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Use PHP_OS_FAMILY if possible

| Q             | A
| ------------- | ---
| Branch?       | 5.2
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

This constant was introduced in PHP 7.2: https://www.php.net/manual/en/reserved.constants.php#constant.php-os-family

~This is not a bug, so if you decide to merge, it should be in 5.4 branch I guess.~

Commits
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0d107cf Use PHP_OS_FAMILY if possible

Author: nicolas-grekas

src/Symfony/Component/Console/Helper/SymfonyQuestionHelper.php

@@ -100,7 +100,7 @@ protected function writeError(OutputInterface $output, \Exception $error)
 
     private function getEofShortcut(): string
     {
-        if (false !== strpos(\PHP_OS, 'WIN')) {
+        if ('Windows' === \PHP_OS_FAMILY) {
             return '<comment>Ctrl+Z</comment> then <comment>Enter</comment>';
         }
 

src/Symfony/Component/Console/Tests/Helper/SymfonyQuestionHelperTest.php

@@ -218,7 +218,7 @@ public function testAskMultilineQuestionIncludesHelpText()
     {
         $expected = 'Write an essay (press Ctrl+D to continue)';
 
-        if (false !== strpos(\PHP_OS, 'WIN')) {
+        if ('Windows' === \PHP_OS_FAMILY) {
             $expected = 'Write an essay (press Ctrl+Z then Enter to continue)';
         }
 

src/Symfony/Component/ErrorHandler/DebugClassLoader.php

@@ -208,7 +208,7 @@ public function __construct(callable $classLoader)
             } elseif (substr($test, -\strlen($file)) === $file) {
                 // filesystem is case insensitive and realpath() normalizes the case of characters
                 self::$caseCheck = 1;
-            } elseif (false !== stripos(\PHP_OS, 'darwin')) {
+            } elseif ('Darwin' === \PHP_OS_FAMILY) {
                 // on MacOSX, HFS+ is case insensitive but realpath() doesn't normalize the case of characters
                 self::$caseCheck = 2;
             } else {