Update ExpressionResultTest.php

Author: staabm

tests/PHPStan/Analyser/ExpressionResultTest.php

@@ -99,6 +99,10 @@ public static function dataIsAlwaysTerminating(): array
 				'exit() ?? $x;',
 				true,
 			],
+			[
+				'(function() { exit(); })();',
+				true,
+			],
 			[
 				'call_user_func(function() { exit(); });',
 				true,