minor #29309 Optimize perf by replacing call_user_func with dynamic variables (ostrolucky)

This PR was merged into the 4.1 branch.

Discussion
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Optimize perf by replacing call_user_func with dynamic variables

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

This provides similar boost as in symfony/symfony#29245, but on more places and without complexity increase. Check eg. https://github.com/fab2s/call_user_func for proof

Fabpot failure unrelated

Commits
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0c6ef01713 Optimize perf by replacing call_user_func with dynamic vars

Author: fabpot

Constraints/CallbackValidator.php

@@ -43,7 +43,7 @@ public function validate($object, Constraint $constraint)
                 throw new ConstraintDefinitionException(sprintf('%s targeted by Callback constraint is not a valid callable', json_encode($method)));
             }
 
-            \call_user_func($method, $object, $this->context, $constraint->payload);
+            $method($object, $this->context, $constraint->payload);
         } elseif (null !== $object) {
             if (!method_exists($object, $method)) {
                 throw new ConstraintDefinitionException(sprintf('Method "%s" targeted by Callback constraint does not exist in class %s', $method, \get_class($object)));

Constraints/ChoiceValidator.php

@@ -53,7 +53,7 @@ public function validate($value, Constraint $constraint)
             ) {
                 throw new ConstraintDefinitionException('The Choice constraint expects a valid callback');
             }
-            $choices = \call_user_func($choices);
+            $choices = $choices();
         } else {
             $choices = $constraint->choices;
         }