Nullif with incorrect valid_count

[YjyJeff]

Describe the bug
The nullif function in compute/kernels/boolean.rs has incorrect valid_count when the left's null_buffer is None.

To Reproduce

let a = Int32Array::from(vec![Some(15), Some(7), Some(8), Some(1), Some(9)]);
let comp = BooleanArray::from(vec![Some(false), None, Some(true), Some(false), None]);
let res = nullif(&a, &comp).unwrap(); // panic here

Why it happens
bitwise_unary_op_helper will apply the op to the remainder bytes, the problem happens here. valid_count will take the ones that should be ignored into consideration.

Solution

let left = Bitmap::new(len);
bitwise_bin_op_helper(left.buffer(), 0, &right, right_offset, len, |l, r| {
    let t = l & !r;
    valid_count += t.count_ones() as usize;
    t
})

[alamb]

label_issue.py automatically added labels {'arrow'} from #3034