Function equal_values 

fn equal_values(
    lhs: &ArrayData,
    rhs: &ArrayData,
    lhs_start: usize,
    rhs_start: usize,
    len: usize,
) -> bool

Compares the values of two ArrayData starting at lhs_start and rhs_start respectively for len slots.

Assumes the null masks of the two ranges are already known to be equal. To compare ranges of child data, use equal_range, which also compares the null masks.