feat(global) make huff_core wasm compatible and add a JS binding

[kanewallmann]

Overview

With some minor tweaks and shims, huff_core can be compiled to a wasm target and then be used with JavaScript which even works in the browser.

1. Remove unused dependency prop-test which is not wasm compatible
2. Shim for into_par_iter() for creating parallel iterators. Not supported on wasm but can just fallback to a regular iterator.
3. SystemTime::now panics on wasm as it's not implemented so use a u64 unix timestamp on wasm target instead.

The biggest change required was to refactor out the file system stuff and create an alternative "in memory" version which loads files from a HashMap instead of from disk.

With that all working, I put together a new module huff_js which includes JavaScript bindings so you can interface with the compiler via a JSON interface similar to standard json in solc.

This would make Huff more accessible to integrate with web-based tools like https://www.evm.codes/ which is why I started looking at this in the first place. It would be awesome to have Huff available on there.

Example JS usage:

const { compile } = require('./pkg/huffc.js')

let files = {
    "add.huff": "#define function add(uint256,uint256) nonpayable returns (uint256)\n" +
        "\n" +
        "#define macro MAIN() = {\n" +
        "   // Load our numbers from calldata and add them together.\n" +
        "   0x04 calldataload // [number1]\n" +
        "   0x24 calldataload // [number2]\n" +
        "   add               // [number1+number2]\n" +
        "   // Return our new number.\n" +
        "   0x00 mstore // Store our number in memory.\n" +
        "   0x20 0x00 return // Return it.\n" +
        "}\n"
}

const result = compile({
    files,
    sources: ['add.huff'],
    // constructor_args: "..."
});

console.log(result)

Outputs:

{
  errors: undefined,
  contracts: Map(1) {
    'add.huff' => {
      bytecode: '600f8060093d393df36004356024350160005260206000f3',
      runtime: '6004356024350160005260206000f3',
      abi: [Object]
    }
  }
}

[Maddiaa0]

Thank you so much for taking this up, so far this looks great!

[Maddiaa0]

Hey @kanewallmann do you have a status update on this one? Let me know if you think its ready to review!

[refcell]

LGTMMM