This is an alternative approach to
https://github.com/ethereum/go-ethereum/pull/31607 , that doesn't break
backwards-compatibility with abigen.
Note that this does change the behavior of `Argument.Pack`: previously,
packing negative values for a `uint` parameter would cause them to be
represented in signed binary representation via two's complement. Now,
it will fail explicitly in this case.
However, I don't see a reason to support this functionality. The ABI
already explicitly supports signed integers. There's no reason that a
smart contract author would choose to store signed values in a `uint`
afaict.
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Co-authored-by: MariusVanDerWijden <m.vanderwijden@live.de>