add support flate2::bufread::DeflateDecoder::new_with_buf

[nil-ref]

I implemented a reader myself, but it can only read up to 32K each time. I tried many methods, and tracked for a long time, and finally found that the problem lies here, zip call flate2::bufread::DeflateDecoder::new is 32K:

impl<R: Read> DeflateDecoder<R> {
    /// Creates a new decoder which will decompress data read from the given
    /// stream.
    pub fn new(r: R) -> DeflateDecoder<R> {
        DeflateDecoder::new_with_buf(r, vec![0; 32 * 1024])
    }
    /// Same as `new`, but the intermediate buffer for data is specified.
    ///
    /// Note that the capacity of the intermediate buffer is never increased,
    /// and it is recommended for it to be large.
    pub fn new_with_buf(r: R, buf: Vec<u8>) -> DeflateDecoder<R> {
        DeflateDecoder {
            inner: bufread::DeflateDecoder::new(BufReader::with_buf(buf, r)),
        }
    }
}

It also provides another interface new_with_buf. But zip does not support it.