Restore app()->getCached*Path() '/' behavior (#32969)

7.2.1 started enforcing DIRECTORY_SEPARATOR
as the path prefix to be treated as absolute.
For a point release, this breaks Windows
environments in existing apps that use
environment variables to set absolute
'/'-prefixed paths.

$_SERVER['APP_CONFIG_CACHE'] = '/ext/cache/config.php';
echo app()->getCachedConfigPath();
// C:\Users\Foo\projects\blog\/ext/cache/config.php

This should still be '/ext/cache/config.php'.

Author: derekmd

src/Illuminate/Foundation/Application.php

@@ -152,7 +152,7 @@ class Application extends Container implements ApplicationContract, CachesConfig
      *
      * @var array
      */
-    protected $absoluteCachePathPrefixes = [DIRECTORY_SEPARATOR];
+    protected $absoluteCachePathPrefixes = ['/', '\\'];
 
     /**
      * Create a new Illuminate application instance.