Nullish input of Big constructor results in Error

[zerosrat]

For example, using Big(null) will cause Error: [big.js] Invalid number while it is common that I can't make sure if the input is not nullish value.

I suggest that Big(null) returns value zero and it logs warning in dev mode.

ref: https://github.com/MikeMcl/big.js/blob/master/big.mjs#L138

[andretf]

IMO not a good idea. BigInt, which is newer than Number, throws error: tc39/proposal-bigint#15