minor symfony#17521 make apc class loader testable against apcu without apc bc layer (Tobion)

This PR was merged into the 2.7 branch.

Discussion
----------

make apc class loader testable against apcu without apc bc layer

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

Commits
-------

24160b3 make apc class loader testable against apcu without apc bc layer

Author: fabpot

src/Symfony/Component/ClassLoader/Tests/ApcClassLoaderTest.php

@@ -14,15 +14,12 @@
 use Symfony\Component\ClassLoader\ApcClassLoader;
 use Symfony\Component\ClassLoader\ClassLoader;
 
-/**
- * @requires extension apc
- */
 class ApcClassLoaderTest extends \PHPUnit_Framework_TestCase
 {
     protected function setUp()
     {
         if (!(ini_get('apc.enabled') && ini_get('apc.enable_cli'))) {
-            $this->markTestSkipped('The apc extension is available, but not enabled.');
+            $this->markTestSkipped('The apc extension is not enabled.');
         } else {
             apcu_clear_cache();
         }