op_exp needs to have a shortcut for 2^e

[AlexeyAkhunov]

There are a lot of contracts on the Ethereum mainnet that were compiled with Solidity prior to the shifting operations were available. For those, exponentiation 2^160 is used to emulate 1<<160. Measurements performed on turbo-geth confirm this. Since we are planning to integrate evmone into turbo-geth, and we have already implemented this shortcut (erigontech/erigon#505), it would be good to maintain that in evmone.

[axic]

I think it would make sense considering an EIP for this, otherwise we are introducing yet another imbalance to "costs".

[AlexeyAkhunov]

I disagree with the notion that every performance improvement needs to lead to the decreasing gas cost. The other way around - yes