Remove some unused variables and properties

src/Symfony/Bundle/FrameworkBundle/Command/ContainerDebugCommand.php

@@ -246,7 +246,7 @@ EOF
         }
 
         try {
-            $r = new \ReflectionClass($serviceId);
+            new \ReflectionClass($serviceId);
 
             return true;
         } catch (\ReflectionException $e) {

src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php

@@ -32,7 +32,7 @@ class TagAwareAdapter implements TagAwareAdapterInterface, PruneableInterface, R
     private $setCacheItemTags;
     private $getTagsByKey;
     private $invalidateTags;
-    private $tagsPool;
+    private $tags;
 
     public function __construct(AdapterInterface $itemsPool, AdapterInterface $tagsPool = null)
     {

src/Symfony/Component/Lock/Store/MemcachedStore.php

@@ -24,12 +24,6 @@ use Symfony\Component\Lock\StoreInterface;
  */
 class MemcachedStore implements StoreInterface
 {
-    private static $defaultClientOptions = array(
-        'persistent_id' => null,
-        'username' => null,
-        'password' => null,
-    );
-
     private $memcached;
     private $initialTtl;
     /** @var bool */

src/Symfony/Component/Yaml/Parser.php

@@ -362,8 +362,6 @@ class Parser
                             @trigger_error($this->getDeprecationMessage(sprintf('Duplicate key "%s" detected whilst parsing YAML. Silent handling of duplicate mapping keys in YAML is deprecated since version 3.2 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0.', $key)), E_USER_DEPRECATED);
                         }
                     } else {
-                        // remember the parsed line number here in case we need it to provide some contexts in error messages below
-                        $realCurrentLineNbKey = $this->getRealCurrentLineNb();
                         $value = $this->parseBlock($this->getRealCurrentLineNb() + 1, $this->getNextEmbedBlock(), $flags);
                         if ('<<' === $key) {
                             $this->refs[$refMatches['ref']] = $value;