> BigDecimal is a commonly used class in business development, It is often
> necessary to perform toString or toPlainString operations on BigDecimal.
>
> The current version uses StringBuilder resulting in multiple memory
> allocations, I made a modification to improve performance.
>
> Because
> I submitted PR #1 before, and there were too many changes. I split it
> into multiple PRs with small changes. This one is one of them.
>
> this PR removed the duplicate code for getChars in
> BigDecimal#StringBuilderHelper, i also make performance faster.
> Please review and don't hesitate
