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.
*/
"use strict";
var autoprefixer = require("autoprefixer");
var calc = require("postcss-calc");
var fs = require("fs");
var gulp = require("gulp");
var postcss = require("gulp-postcss");
var rename = require("gulp-rename");
var replace = require("gulp-replace");
var mkdirp = require("mkdirp");
var path = require("path");
var rimraf = require("rimraf");
var stream = require("stream");
var exec = require("child_process").exec;
var spawn = require("child_process").spawn;
var spawnSync = require("child_process").spawnSync;
var streamqueue = require("streamqueue");
var merge = require("merge-stream");
var zip = require("gulp-zip");
var webpack2 = require("webpack");
var webpackStream = require("webpack-stream");
var Vinyl = require("vinyl");
var vfs = require("vinyl-fs");
var through = require("through2");
var BUILD_DIR = "build/";
var L10N_DIR = "l10n/";
var TEST_DIR = "test/";
var EXTENSION_SRC_DIR = "extensions/";
var BASELINE_DIR = BUILD_DIR + "baseline/";
var MOZCENTRAL_BASELINE_DIR = BUILD_DIR + "mozcentral.baseline/";