Added regression test

Author: staabm

tests/PHPStan/Rules/Functions/CallToNonExistentFunctionRuleTest.php

@@ -280,4 +280,20 @@ public function testBug8980(): void
 		]);
 	}
 
+	public function testBug11359(): void
+	{
+		$errors = [];
+		if (PHP_VERSION_ID < 80400) {
+			$errors = [
+				[
+					'Function mb_ucfirst not found.',
+					3,
+					'Learn more at https://phpstan.org/user-guide/discovering-symbols',
+				]
+			];
+		}
+		$this->analyse([__DIR__ . '/data/bug-11359.php'], $errors);
+	}
+
+
 }

tests/PHPStan/Rules/Functions/data/bug-11359.php

@@ -0,0 +1,3 @@
+<?php declare(strict_types = 1);
+
+print mb_ucfirst('hello');