Invalid return type annotation when generating stubs

[sergeyklay]

When generating stubs, only existing and valid data types should be used.

Zephir code:

    public function test() -> char
    {
        char a = 'A';

        return a;
    }

Expected result:

    /**
     * @return int
     */
    public function test(): int
    {
    }

Actual result:

    /**
     * @return char
     */
    public function test(): int
    {
    }

[sergeyklay]

Fixed in the development branch.