use deterministic CREATE2 opcode

[rainbreak]

Constantinople will add the CREATE2 opcode, which has contract addresses that are a function of the code hash. This would remove the need for caching.

https://eips.ethereum.org/EIPS/eip-1014

[PaulRBerg]

This would remove the need for caching.

A hypothetical execute function that renounces caching would need the deployer address, the salt, and the construction bytecode as parameters.

What do you do if no contract is found for that set of parameters? Do you deploy it via the DSProxy? Do you revert? Users might prefer to use their own factories instead of letting the DSProxy do this.