bug #31442 [Validator] Fix finding translator parent definition in co…

…mpiler pass (deguif)

This PR was merged into the 4.2 branch.

Discussion
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[Validator] Fix finding translator parent definition in compiler pass

| Q             | A
| ------------- | ---
| Branch?       | 4.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Method `ChildDefintion::getParent()` returns a string, but here it is expected to return an object of class `Definition` in order to call `getClass` on it in the loop.

Commits
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d261bb5 Fix finding parent definition

src/Symfony/Component/Validator/DependencyInjection/AddValidatorInitializersPass.php

@@ -62,7 +62,7 @@ public function process(ContainerBuilder $container)
                 }
 
                 while (!($class = $translator->getClass()) && $translator instanceof ChildDefinition) {
-                    $translator = $translator->getParent();
+                    $translator = $container->findDefinition($translator->getParent());
                 }
 
                 if (!is_subclass_of($class, LegacyTranslatorInterface::class)) {