feat: add filecoin chains

[AmeanAsad]

Motivation

Adding Filecoin chains into the Chain enum. Filecoin is launching its own virtual machine and adding the Filecoin chains into ethers-rs allows developers to use them in the rust web3 tooling. The main personal use I have is estimating chain gas costs when using Foundry to deploy smart contracts on the Filecoin virtual machine.

Solution

Added filecoin chains into the Chain enum and the other corresponding spots required for their definition.

PR Checklist

• Added Tests (N/A)
• Added Documentation (N/A)
• Updated the changelog
• Breaking changes

[mattsse]

are these compatible with etherscan API?

[AmeanAsad]

They are not

[gakonst]

Hmm then we cannot use them. We could make verification just not work on foundry but doubt we'll want to add special handling here

Where can we read more about the filecoin evm spec?

[AmeanAsad]

@gakonst Here are some resources regarding docs/specs:

• Spec
• Official docs

[prestwich]

we can't guarantee that ethers will behave properly for any virtualized EVM 🤔

[AmeanAsad]

@prestwich the filecoin virtual machine is EVM compatible (idk if that helps). The main reason for this request is to enable gas estimation in Foundry which uses ethers Chain enum. As of now that is the only functionality required from this change. Is that acceptable?

[prestwich]

the FVM has a virtualized EVM, this is not necessarily the same thing as being EVM-compatible 😅

[DaniPopes]

I think this is ok, given that:

• it's on Chainlist
• they have docs for usage with Metamask and Hardhat

Although they have their own precompiles

[gakonst]

K - given no block explorer handlign im fine w this