Merge branch '2.7' into 2.8

* 2.7:
  Permit empty suffix on Windows
  [Console][Table] fixed render when using multiple rowspans.
  add docblocks for Twig url and path function to improve ide completion
  check for circular refs caused by method calls
  [Serializer] fix upper camel case conversion (see #21399)
  [DI] Auto register extension configuration classes as a resource
  [Console] Updated phpdoc on return types

ExecutableFinder.php

@@ -75,7 +75,7 @@ public function find($name, $default = null, array $extraDirs = array())
         $suffixes = array('');
         if ('\\' === DIRECTORY_SEPARATOR) {
             $pathExt = getenv('PATHEXT');
-            $suffixes = $pathExt ? explode(PATH_SEPARATOR, $pathExt) : $this->suffixes;
+            $suffixes = array_merge($suffixes, $pathExt ? explode(PATH_SEPARATOR, $pathExt) : $this->suffixes);
         }
         foreach ($suffixes as $suffix) {
             foreach ($dirs as $dir) {