[DeadCode] Skip foreach over side-effecting expression in RemoveDeadIfForeachForRector

[TomasVotruba]

Problem

RemoveDeadIfForeachForRector removed a foreach with an empty body even when the iterated expression has side effects, e.g. consuming a generator:

public function run(): WorkflowState
{
    if (! isset($this->result)) {
        foreach ($this->events() as $event) {
        }
    }

    return $this->result;
}

Here $this->events() is a generator that sets $this->result as it is consumed. The empty body is not dead code — iterating is the work. The rule deleted the whole if/foreach, silently breaking behavior.

Spotted in the wild: https://github.com/neuron-core/neuron-ai/blob/3.x/rector.php#L23-L27 had to withSkip() this rule on WorkflowHandler.php.

Fix

processForForeach() only checked whether loop variables were used in the next statement; it ignored side effects in the iterated expression itself. Bail out when $for->expr contains a CallLike/Assign (reusing the existing hasNodeSideEffect() helper already used by processIf()).

Added skip_foreach_over_call_side_effect.php.inc fixture covering the case.

[TomasVotruba]

Fixed skip in https://github.com/neuron-core/neuron-ai/blob/3.x/rector.php#L23-L27