remove deprecated features

Author: xabbuh

Mapping/Loader/YamlFileLoader.php

@@ -115,18 +115,10 @@ protected function parseNodes(array $nodes)
      */
     private function parseFile($path)
     {
-        $prevErrorHandler = set_error_handler(function ($level, $message, $script, $line) use ($path, &$prevErrorHandler) {
-            $message = E_USER_DEPRECATED === $level ? preg_replace('/ on line \d+/', ' in "'.$path.'"$0', $message) : $message;
-
-            return $prevErrorHandler ? $prevErrorHandler($level, $message, $script, $line) : false;
-        });
-
         try {
             $classes = $this->yamlParser->parseFile($path, Yaml::PARSE_CONSTANT);
         } catch (ParseException $e) {
             throw new \InvalidArgumentException(sprintf('The file "%s" does not contain valid YAML.', $path), 0, $e);
-        } finally {
-            restore_error_handler();
         }
 
         // empty file