Merge branch '4.1' into 4.2

* 4.1:
  Fix typos in doc blocks
  [Debug] ignore underscore vs backslash namespaces in DebugClassLoader
  [TwigBridge][Form] Prevent multiple rendering of form collection prototypes
  [FrameworkBundle] fix describing routes with no controllers
  [DI] move RegisterServiceSubscribersPass before DecoratorServicePass
  Update ValidationListener.php
  [Yaml] ensures that the mb_internal_encoding is reset to its initial value
  [WebLink] Fixed documentation link
  [Security] getTargetPath of TargetPathTrait must return string or null
  [Hackday][Serializer] Deserialization ignores argument type hint from phpdoc for array in constructor argument
  Optimize perf by replacing call_user_func with dynamic vars
  [Routing] fix dumping same-path routes with placeholders
  [Security] defer log message in guard authenticator
  [Validator] Added IBAN format for Vatican City State
  merge conflicts
  filter out invalid Intl values
  filter out invalid language values
  [Validator] Fixed grouped composite constraints
  [Form] Filter arrays out of scalar form types
  Fix HeaderBag::get phpdoc

Author: nicolas-grekas

Debug/OptionsResolverIntrospector.php

@@ -47,7 +47,7 @@ public function __construct(OptionsResolver $optionsResolver)
      */
     public function getDefault(string $option)
     {
-        return \call_user_func($this->get, 'defaults', $option, sprintf('No default value was set for the "%s" option.', $option));
+        return ($this->get)('defaults', $option, sprintf('No default value was set for the "%s" option.', $option));
     }
 
     /**
@@ -57,7 +57,7 @@ public function getDefault(string $option)
      */
     public function getLazyClosures(string $option): array
     {
-        return \call_user_func($this->get, 'lazy', $option, sprintf('No lazy closures were set for the "%s" option.', $option));
+        return ($this->get)('lazy', $option, sprintf('No lazy closures were set for the "%s" option.', $option));
     }
 
     /**
@@ -67,7 +67,7 @@ public function getLazyClosures(string $option): array
      */
     public function getAllowedTypes(string $option): array
     {
-        return \call_user_func($this->get, 'allowedTypes', $option, sprintf('No allowed types were set for the "%s" option.', $option));
+        return ($this->get)('allowedTypes', $option, sprintf('No allowed types were set for the "%s" option.', $option));
     }
 
     /**
@@ -77,15 +77,15 @@ public function getAllowedTypes(string $option): array
      */
     public function getAllowedValues(string $option): array
     {
-        return \call_user_func($this->get, 'allowedValues', $option, sprintf('No allowed values were set for the "%s" option.', $option));
+        return ($this->get)('allowedValues', $option, sprintf('No allowed values were set for the "%s" option.', $option));
     }
 
     /**
      * @throws NoConfigurationException on no configured normalizer
      */
     public function getNormalizer(string $option): \Closure
     {
-        return \call_user_func($this->get, 'normalizers', $option, sprintf('No normalizer was set for the "%s" option.', $option));
+        return ($this->get)('normalizers', $option, sprintf('No normalizer was set for the "%s" option.', $option));
     }
 
     /**
@@ -95,6 +95,6 @@ public function getNormalizer(string $option): \Closure
      */
     public function getDeprecationMessage(string $option)
     {
-        return \call_user_func($this->get, 'deprecated', $option, sprintf('No deprecation was set for the "%s" option.', $option));
+        return ($this->get)('deprecated', $option, sprintf('No deprecation was set for the "%s" option.', $option));
     }
 }