Convert Log from class to a function

[marvinhagemeister]

This PR rewrites Log as a simple function that returns a plain object. This change slightly improves the final bundle size by removing an iife.

Bundled output before this PR:

var Log = /** @class */ (function () {
  function Log() {
    this.node1 = null;
    this.node1slot = 0;
    this.nodes = null;
    this.nodeslots = null;
  }
  return Log;
}());

After this PR:

function Log() {
  return {
    node1: null,
    node1slot: 0,
    nodes: null,
    nodeslots: null
  };
}