https://mikemcl.github.io/big.js
/**
* [a,1,1,1] low:[b,1,1,1]
* 结果： a × 2 ^ 32 + b=
* ( 2 ^ 32 - 1 ) × 2 ^ 32 + 2 ^ 32 - 1
* var aa = (new Big(2 ** 32)).minus(1).times(2 ** 32).plus(2 ** 32).minus(1);
* readme:https://mikemcl.github.io/big.js
*/