scripts/build/bundler.mjs/getBabelConfig
function getBabelConfig(bundle) {
  const config = {
    babelrc: false,
    assumptions: {
      setSpreadProperties: true,
    },
    sourceType: "unambiguous",
    plugins: bundle.babelPlugins || [],
    compact: false,
    exclude: [/\/core-js\//],
  };
  const targets = { node: "10" };
  if (bundle.target === "universal") {
    targets.browsers = packageJson.browserslist;
  }
  config.presets = [
    [
      "@babel/preset-env",
      {
        targets,
        exclude: [
          "es.array.unscopables.flat",
          "es.array.unscopables.flat-map",
          "es.array.sort",
          "es.promise",
          "es.promise.finally",
          "es.string.replace",
          "es.symbol.description",
          "es.typed-array.*",
          "web.*",
        ],
        modules: false,
        useBuiltIns: "usage",
        corejs: {
          version: 3,
        },
        debug: false,
      },
    ],
  ];
  config.plugins.push([
    "@babel/plugin-proposal-object-rest-spread",
    { useBuiltIns: true },
  ]);
  return config;
}