[Binding] Incorrect data extension for get_bit

[chhzh123]

The following binary convolution kernel generates incorrect results which is due to incorrect data extension of get_bit.

def test_bconv2D_nhwc_packed():
    hcl.init(hcl.UInt(packing_factor))
    A = hcl.placeholder((bs, ih, iw, ic // packing_factor))
    F = hcl.placeholder((oc, kh, kw, ic // packing_factor))

    def conv(A, F):
        rc = hcl.reduce_axis(0, ic // packing_factor)
        rh = hcl.reduce_axis(0, kh)
        rw = hcl.reduce_axis(0, kw)
        rb = hcl.reduce_axis(0, ic)
        L = ic * kh * kw
        B = hcl.compute(
            (bs, oh, ow, oc),
            lambda n, h, w, c: L
            - (
                hcl.sum(
                    (A[n, h + rh, w + rw, rc] ^ F[c, rh, rw, rc])[rb],
                    axis=[rh, rw, rc, rb],
                    dtype=hcl.Int(32),
                )
                << 1
            ),
            name="B",
            dtype=hcl.Int(32),
        )
        return B

    s = hcl.create_schedule([A, F], conv)

The original code uses signed extension, which is not the case. Since the obtained one-bit integer is unsigned, we should use unsigned extension.

%8 = hcl.get_bit(%7 : i16, %arg9) -> i1
%10 = arith.extsi %8 : i1 to i32