Fix conditional expression filtering in processAlwaysIterableForeachScopeWithoutPollute

The previous approach (using $finalScope->conditionalExpressions filtered
to $this variables) lost valid conditional expressions that existed in
$this but not in $finalScope, causing false positives like "Call to an
undefined method PhpParser\Node::getReturnType()".

The correct approach: start from $this->conditionalExpressions (pre-foreach)
and remove only entries where a condition variable's type changed between
$this and $finalScope, indicating it was reassigned in the foreach body
and the conditional expression is stale. When a type change is detected,
the entire conditional expression key is removed (not individual holders)
to avoid partial/inconsistent state.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Analyser/MutatingScope.php

@@ -3870,24 +3870,22 @@ public function processAlwaysIterableForeachScopeWithoutPollute(self $finalScope
 			);
 		}
 
-		$conditionalExpressions = [];
-		foreach ($finalScope->conditionalExpressions as $conditionalExprString => $holders) {
-			if (!isset($this->expressionTypes[$conditionalExprString])) {
-				continue;
-			}
-			$filteredHolders = [];
+		$conditionalExpressions = $this->conditionalExpressions;
+		foreach ($this->conditionalExpressions as $conditionalExprString => $holders) {
 			foreach ($holders as $holder) {
-				foreach (array_keys($holder->getConditionExpressionTypeHolders()) as $holderExprString) {
+				foreach ($holder->getConditionExpressionTypeHolders() as $holderExprString => $condTypeHolder) {
+					if (!isset($finalScope->expressionTypes[$holderExprString])) {
+						continue 2;
+					}
 					if (!isset($this->expressionTypes[$holderExprString])) {
 						continue 2;
 					}
+					if (!$this->expressionTypes[$holderExprString]->getType()->equals($finalScope->expressionTypes[$holderExprString]->getType())) {
+						unset($conditionalExpressions[$conditionalExprString]);
+						continue 3;
+					}
 				}
-				$filteredHolders[] = $holder;
-			}
-			if ($filteredHolders === []) {
-				continue;
 			}
-			$conditionalExpressions[$conditionalExprString] = $filteredHolders;
 		}
 
 		return $this->scopeFactory->create(