Development Task

When estimating the number of rows for ranges in GetColumnRowCount, if the range is out-of-range, for example, the range's upper bound is less than the minimum value in statistics, TiDB uses outOfRangeEQSelectivity, but this is inappropriate since outOfRangeEQSelectivity is created for point estimation instead of range estimation.
It's better to create a new function outOfRangeIntervalSelectivity for range estimation.

This function outOfRangeIntervalSelectivity can be implemented as:

func outOfRangeIntervalSelectivity(range, modifyCount) float64 {
    stat_width = stat_maximum - stat-minimum
    range_width = range_upper - range_lower
    range_count = stat_total_count * (range_width / stat_width)
    return min(range_count, modifyCount)
}