Change FunctionCallableVariant::isBuiltin() to return TrinaryLogic

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

Author: phpstan-bot

src/Reflection/Callables/FunctionCallableVariant.php

@@ -179,14 +179,14 @@ public function getAsserts(): Assertions
 		return $this->function->getAsserts();
 	}
 
-	public function isBuiltin(): bool
+	public function isBuiltin(): TrinaryLogic
 	{
 		$isBuiltin = $this->function->isBuiltin();
 		if ($isBuiltin instanceof TrinaryLogic) {
-			return $isBuiltin->yes();
+			return $isBuiltin;
 		}
 
-		return $isBuiltin;
+		return TrinaryLogic::createFromBoolean($isBuiltin);
 	}
 
 }

src/Type/CallableType.php

@@ -181,7 +181,7 @@ private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSup
 
 		$variantsResult = null;
 		foreach ($type->getCallableParametersAcceptors($scope) as $variant) {
-			$isBuiltinCallable = $variant instanceof FunctionCallableVariant && $variant->isBuiltin();
+			$isBuiltinCallable = $variant instanceof FunctionCallableVariant && $variant->isBuiltin()->yes();
 			$variant = ParametersAcceptorSelector::selectFromTypes($parameterTypes, [$variant], false);
 			if (!$variant instanceof CallableParametersAcceptor) {
 				return IsSuperTypeOfResult::createNo([]);