https://twitter.com/therealyashsriv/status/1219691914523545601

We shouldn't generate code that might cause browser or linting to complain.

https://github.com/facebook/react/blob/0cf22a56a18790ef34c71bef14f64695c0498619/packages/legacy-events/SyntheticEvent.js#L259

It's also just a confusing pattern at best.
'use strict';
const {
  es5Paths,
  esNextPaths,
} = require('./scripts/shared/pathsByLanguageVersion');
const restrictedGlobals = require('confusing-browser-globals');
const OFF = 0;