Unify the way to provide expression functions for the DI container

Function providers registered on the ContainerBuilder are now reused by
the PhpDumper when dumping the container instead of forcing to register
them again.
Closes #13012

Author: stof

ContainerBuilder.php

@@ -1075,6 +1075,14 @@ public function addExpressionLanguageProvider(ExpressionFunctionProviderInterfac
         $this->expressionLanguageProviders[] = $provider;
     }
 
+    /**
+     * @return ExpressionFunctionProviderInterface[]
+     */
+    public function getExpressionLanguageProviders()
+    {
+        return $this->expressionLanguageProviders;
+    }
+
     /**
      * Returns the Service Conditionals.
      *

Dumper/PhpDumper.php

@@ -1399,6 +1399,11 @@ public function dumpParameter($name)
         return sprintf("\$this->getParameter('%s')", strtolower($name));
     }
 
+    /**
+     * @deprecated Deprecated since 2.6.2, to be removed in 3.0. Use Symfony\Component\DependencyInjection\ContainerBuilder::addExpressionLanguageProvider instead.
+     *
+     * @param ExpressionFunctionProviderInterface $provider
+     */
     public function addExpressionLanguageProvider(ExpressionFunctionProviderInterface $provider)
     {
         $this->expressionLanguageProviders[] = $provider;
@@ -1493,7 +1498,8 @@ private function getExpressionLanguage()
             if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
                 throw new RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
             }
-            $this->expressionLanguage = new ExpressionLanguage(null, $this->expressionLanguageProviders);
+            $providers = array_merge($this->container->getExpressionLanguageProviders(), $this->expressionLanguageProviders);
+            $this->expressionLanguage = new ExpressionLanguage(null, $providers);
         }
 
         return $this->expressionLanguage;