Upstream support for deposit transactions to anvil

[mdehoog]

anvil currently does not support the op-stack's deposit transaction.

This has resulted in a workaround in this codebase:

• read deposit transactions from the payload passed to the engine API from op-node
• use anvil_setBalance to increase the balance, according to the deposit tx's mint value
• use anvil_impersonateAccount + eth_sendTransaction to send the deposit transaction as a legacy tx in anvil

op-node also expects deposit transactions to be returned on the RPC, so we also:

• rewrite any requests that include the deposit tx hash, and replace them with the hash of the legacy tx we created
• rewrite any responses that include the legacy tx, and replace them with the deposit tx

This is hacky and flaky. The ideal path is to upstream support for op-stack deposit transactions in anvil itself (probably behind a flag). This would mean we submit deposit txs directly to anvil, and remove the request / response rewriting.

[roninjin10]

Since this got posted on twitter, note this is happening via op-reth already. No need to duplicate work here

[mdehoog]

WIP branch here: https://github.com/mdehoog/foundry/tree/op-deposit

[roninjin10]

ethereum-optimism#4