added regression test

Author: staabm

tests/PHPStan/Rules/DeadCode/UnreachableStatementRuleTest.php

@@ -361,4 +361,10 @@ public function testBug13311(): void
 		$this->analyse([__DIR__ . '/data/bug-13311.php'], []);
 	}
 
+	public function testBug13331(): void
+	{
+		$this->treatPhpDocTypesAsCertain = false;
+		$this->analyse([__DIR__ . '/data/bug-13331.php'], []);
+	}
+
 }

tests/PHPStan/Rules/DeadCode/data/bug-13331.php

@@ -0,0 +1,12 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13331;
+
+$signalHandler = function () {
+	exit();
+};
+
+pcntl_async_signals(true);
+pcntl_signal(SIGINT, $signalHandler);
+pcntl_signal(SIGQUIT, $signalHandler);
+pcntl_signal(SIGTERM, $signalHandler);