Can't use empty for method argument type array.

Hi, i am tried use empty operator for array input argument, but zephir fail it.

Simple example:

class Arr{
    public function isEmpty(const array args = NULL) -> bool{
        if empty args {
            return true;
        } else {
            return false;
        }
    }
}

Output:

Zephir\CompilerException: Only dynamic/string variables can be used in 'empty' operators in /var/www/it/arr.zep on line 5

       if empty args {

----------------------^

Zephir knows that args is array, bat throw error.

I think it's a bug, did you report it?