Temporarily fix tests.

tests/utf8_variables.aer

@@ -13,11 +13,11 @@ class Program {
 	}
 
 	private function isUTF8(string $str) {
-		$b = 0;
-		$c = 0;
-		$bits = 0;
-		$len = strlen($str);
-		for($i = 0; $i < $len; $i++) {
+		int $b = 0;
+		int $c = 0;
+		int $bits = 0;
+		int $len = strlen($str);
+		for(int $i = 0; $i < $len; $i++) {
 			$c = ord($str[$i]);
 			if($c >= 128) {
 				if(($c >= 254)) return false;