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.
"minified-pre",
  gulp.series(
    "buildnumber",
    "default_preferences",
    "locale",
    function scripting() {
      var defines = builder.merge(DEFINES, { MINIFIED: true, GENERIC: true });
      return createTemporaryScriptingBundle(defines);
    },
    function () {
      console.log();
      console.log("### Creating minified viewer");
      var defines = builder.merge(DEFINES, { MINIFIED: true, GENERIC: true });
      return buildMinified(defines, MINIFIED_DIR);
    }
  )
);
gulp.task(
  "minified-legacy-pre",
  gulp.series(
    "buildnumber",
    "default_preferences",
    "locale",
    function scripting() {
      var defines = builder.merge(DEFINES, {
        MINIFIED: true,
        GENERIC: true,
        SKIP_BABEL: false,
      });
      return createTemporaryScriptingBundle(defines);