Add support for "browser" condition (e.g., as used by Webpack) by stubbing-away Node imports (fixes #1441).

lib/node-imports-browser.mjs

@@ -0,0 +1,22 @@
+// @ts-check
+
+const getError = () => new Error("Node APIs are not available in browser context.");
+const throwForSync = () => {
+  throw getError();
+};
+
+export const fs = {
+  "access": (path, callback) => callback(getError()),
+  "accessSync": throwForSync,
+  "readFile": (path, options, callback) => callback(getError()),
+  "readFileSync": throwForSync
+};
+
+export { default as module } from "./node-imports-browser-module.cjs";
+
+export const os = {};
+
+export const path = {
+  "dirname": throwForSync,
+  "resolve": throwForSync
+};