bug #29875 [TwigBridge] fix compatibility with Twig >= 2.6.1 (xabbuh)

This PR was merged into the 3.4 branch.

Discussion
----------

[TwigBridge] fix compatibility with Twig >= 2.6.1

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | twigphp/Twig#2803
| License       | MIT
| Doc PR        |

Commits
-------

40089fb fix compatibility with Twig >= 2.6.1

src/Symfony/Bridge/Twig/TokenParser/TransChoiceTokenParser.php

@@ -68,7 +68,7 @@ public function parse(Token $token)
         $body = $this->parser->subparse(array($this, 'decideTransChoiceFork'), true);
 
         if (!$body instanceof TextNode && !$body instanceof AbstractExpression) {
-            throw new SyntaxError('A message inside a transchoice tag must be a simple text.', $body->getTemplateLine(), $stream->getSourceContext()->getName());
+            throw new SyntaxError('A message inside a transchoice tag must be a simple text.', $body->getTemplateLine(), $stream->getSourceContext());
         }
 
         $stream->expect(Token::BLOCK_END_TYPE);

src/Symfony/Bridge/Twig/TokenParser/TransTokenParser.php

@@ -60,7 +60,7 @@ public function parse(Token $token)
                 $stream->next();
                 $locale = $this->parser->getExpressionParser()->parseExpression();
             } elseif (!$stream->test(Token::BLOCK_END_TYPE)) {
-                throw new SyntaxError('Unexpected token. Twig was looking for the "with", "from", or "into" keyword.', $stream->getCurrent()->getLine(), $stream->getSourceContext()->getName());
+                throw new SyntaxError('Unexpected token. Twig was looking for the "with", "from", or "into" keyword.', $stream->getCurrent()->getLine(), $stream->getSourceContext());
             }
         }
 
@@ -69,7 +69,7 @@ public function parse(Token $token)
         $body = $this->parser->subparse(array($this, 'decideTransFork'), true);
 
         if (!$body instanceof TextNode && !$body instanceof AbstractExpression) {
-            throw new SyntaxError('A message inside a trans tag must be a simple text.', $body->getTemplateLine(), $stream->getSourceContext()->getName());
+            throw new SyntaxError('A message inside a trans tag must be a simple text.', $body->getTemplateLine(), $stream->getSourceContext());
         }
 
         $stream->expect(Token::BLOCK_END_TYPE);