Added regression test

Author: staabm

tests/PHPStan/Rules/Comparison/ConstantLooseComparisonRuleTest.php

@@ -225,4 +225,15 @@ public function testBug11694(): void
 		$this->analyse([__DIR__ . '/data/bug-11694.php'], $expectedErrors);
 	}
 
+	public function testBug8800(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-8800.php'], [
+			[
+				'Loose comparison using == between 0|1|false and 2 will always evaluate to false.',
+				9,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-8800.php

@@ -0,0 +1,11 @@
+<?php declare(strict_types=1);
+
+namespace Bug8800;
+
+class HelloWorld
+{
+	public function sayHello(string $s): void
+	{
+		var_dump(preg_match('{[A-Z]}', $s) == 2);
+	}
+}