On https://github.com/mozilla/pdf.js/wiki/Required-Browser-Features we mention required browser features for PDF.js, but I have the feeling that not all of them are necessary nowadays since we moved to using more modern features over the years. Moreover, as indicated in https://github.com/mozilla/pdf.js/issues/11950#issuecomment-637149085, some features may be missing such as range requests or `async/await`.

In short, we should verify which are still necessary and update the wiki page and the automated feature detection if possible.
],
    }).code;
    var removeCjsSrc = /^(var\s+\w+\s*=\s*(_interopRequireDefault\()?require\(".*?)(?:\/src)(\/[^"]*"\)\)?;)$/gm;
    content = content.replace(removeCjsSrc, (all, prefix, interop, suffix) => {
      return prefix + suffix;
    });
    return licenseHeaderLibre + content;
  }
  var babel = require("@babel/core");
  var versionInfo = getVersionJSON();
  var bundleDefines = builder.merge(defines, {
    BUNDLE_VERSION: versionInfo.version,
    BUNDLE_BUILD: versionInfo.commit,
    TESTING: process.env.TESTING === "true",
  });
  var ctx = {
    rootPath: __dirname,
    saveComments: false,
    defines: bundleDefines,
    map: {
      "pdfjs-lib": "../pdf",
    },
  };
  var licenseHeaderLibre = fs
    .readFileSync("./src/license_header_libre.js")
    .toString();
  var preprocessor2 = require("./external/builder/preprocessor2.js");
  return merge([
    gulp.src(
      [