free token cache in clover report

Author: oker1

PHP/CodeCoverage/Report/Clover.php

@@ -120,11 +120,13 @@ public function process(PHP_CodeCoverage $coverage, $target = NULL, $name = NULL
                 $tokens        = PHP_Token_Stream_CachingFactory::get($filename);
                 $classesInFile = $tokens->getClasses();
                 $linesOfCode   = $tokens->getLinesOfCode();
-                unset($tokens);
 
                 $ignoredLines = PHP_CodeCoverage_Util::getLinesToBeIgnored(
                   $filename
                 );
+                
+                PHP_Token_Stream_CachingFactory::unsetFromCache($filename);
+                unset($tokens);
 
                 $lines = array();