bug #20676 [ClassLoader] Use only forward slashes in generated class …

…map (nicolas-grekas)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #20676).

Discussion
----------

[ClassLoader] Use only forward slashes in generated class map

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #20655
| License       | MIT
| Doc PR        | -

Commits
-------

6d1f1b5 [ClassLoader] Use only forward slashes in generated class map

src/Symfony/Component/ClassLoader/ClassCollectionLoader.php

@@ -63,7 +63,7 @@ public static function load($classes, $cacheDir, $name, $autoReload, $adaptive =
             throw new \RuntimeException(sprintf('Class Collection Loader was not able to create directory "%s"', $cacheDir));
         }
         $cacheDir = rtrim(realpath($cacheDir) ?: $cacheDir, '/'.DIRECTORY_SEPARATOR);
-        $cache = $cacheDir.DIRECTORY_SEPARATOR.$name.$extension;
+        $cache = $cacheDir.'/'.$name.$extension;
 
         // auto-reload
         $reload = false;
@@ -114,7 +114,7 @@ public static function load($classes, $cacheDir, $name, $autoReload, $adaptive =
 REGEX;
         $dontInlineRegex = str_replace('.', $spacesRegex, $dontInlineRegex);
 
-        $cacheDir = explode(DIRECTORY_SEPARATOR, $cacheDir);
+        $cacheDir = explode('/', str_replace(DIRECTORY_SEPARATOR, '/', $cacheDir));
         $files = array();
         $content = '';
         foreach (self::getOrderedClasses($classes) as $class) {
@@ -126,19 +126,19 @@ public static function load($classes, $cacheDir, $name, $autoReload, $adaptive =
             $c = file_get_contents($file);
 
             if (preg_match($dontInlineRegex, $c)) {
-                $file = explode(DIRECTORY_SEPARATOR, $file);
+                $file = explode('/', str_replace(DIRECTORY_SEPARATOR, '/', $file));
 
                 for ($i = 0; isset($file[$i], $cacheDir[$i]); ++$i) {
                     if ($file[$i] !== $cacheDir[$i]) {
                         break;
                     }
                 }
                 if (1 >= $i) {
-                    $file = var_export(implode(DIRECTORY_SEPARATOR, $file), true);
+                    $file = var_export(implode('/', $file), true);
                 } else {
                     $file = array_slice($file, $i);
-                    $file = str_repeat('..'.DIRECTORY_SEPARATOR, count($cacheDir) - $i).implode(DIRECTORY_SEPARATOR, $file);
-                    $file = '__DIR__.'.var_export(DIRECTORY_SEPARATOR.$file, true);
+                    $file = str_repeat('../', count($cacheDir) - $i).implode('/', $file);
+                    $file = '__DIR__.'.var_export('/'.$file, true);
                 }
 
                 $c = "\nnamespace {require $file;}";