module: refactor internal/module export style

PR-URL: https://github.com/nodejs/node/pull/12644
Reviewed-By: Brian White <mscdex@mscdex.net>

lib/internal/module.js

@@ -1,14 +1,5 @@
 'use strict';
 
-exports = module.exports = {
-  makeRequireFunction,
-  stripBOM,
-  stripShebang,
-  addBuiltinLibsToObject
-};
-
-exports.requireDepth = 0;
-
 // Invoke with makeRequireFunction(module) where |module| is the Module object
 // to use as the context for the require() function.
 function makeRequireFunction(mod) {
@@ -85,7 +76,7 @@ function stripShebang(content) {
   return content;
 }
 
-exports.builtinLibs = [
+const builtinLibs = [
   'assert', 'buffer', 'child_process', 'cluster', 'crypto', 'dgram', 'dns',
   'domain', 'events', 'fs', 'http', 'https', 'net', 'os', 'path', 'punycode',
   'querystring', 'readline', 'repl', 'stream', 'string_decoder', 'tls', 'tty',
@@ -94,7 +85,7 @@ exports.builtinLibs = [
 
 function addBuiltinLibsToObject(object) {
   // Make built-in modules available directly (loaded lazily).
-  exports.builtinLibs.forEach((name) => {
+  builtinLibs.forEach((name) => {
     // Goals of this mechanism are:
     // - Lazy loading of built-in modules
     // - Having all built-in modules available as non-enumerable properties
@@ -130,3 +121,12 @@ function addBuiltinLibsToObject(object) {
     });
   });
 }
+
+module.exports = exports = {
+  addBuiltinLibsToObject,
+  builtinLibs,
+  makeRequireFunction,
+  requireDepth: 0,
+  stripBOM,
+  stripShebang
+};