minor #17659 [ClassLoader] fix ApcClassLoader tests on HHVM (xabbuh)

This PR was merged into the 3.0 branch.

Discussion
----------

[ClassLoader] fix ApcClassLoader tests on HHVM

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

Commits
-------

db1c635 [ClassLoader] fix ApcClassLoader tests on HHVM

composer.json

@@ -80,6 +80,7 @@
         "monolog/monolog": "~1.11",
         "ocramius/proxy-manager": "~0.4|~1.0",
         "egulias/email-validator": "~1.2",
+        "symfony/polyfill-apcu": "~1.1",
         "symfony/security-acl": "~2.8|~3.0",
         "phpdocumentor/reflection": "^1.0.7"
     },

src/Symfony/Component/ClassLoader/composer.json

@@ -20,7 +20,8 @@
         "php": ">=5.5.9"
     },
     "require-dev": {
-        "symfony/finder": "~2.8|~3.0"
+        "symfony/finder": "~2.8|~3.0",
+        "symfony/polyfill-apcu": "~1.1"
     },
     "suggest": {
         "symfony/polyfill-apcu": "For using ApcClassLoader on HHVM"