Implement native function of least(84)

[guixiaowen]

Description

Convert Spark's built-in function least to execute as a native function.

Spark function name:
least

Method description:

least(expr, ...) - Returns the least value of all parameters, skipping null values.

Examples:

SELECT least(10, 9, 2, 4, 3);
2

To Native function

f::core::least()