Rewrite the following AST of `sum(column + literal)`
sum(column + literal) -> sum(column) + literal * count(column)
sum(literal + column) -> sum(column) + literal * count(column)
Test the patch on 2 x 80 vCPUs system, Q29 of ClickBench has got a huge
11.5x performance improvement.
Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
