Make babel-register 7.x backward-compatible with 6.x. (#6268)

packages/babel-register/package.json

@@ -5,8 +5,10 @@
   "license": "MIT",
   "repository": "https://github.com/babel/babel/tree/master/packages/babel-register",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
-  "main": "lib/node.js",
-  "browser": "lib/browser.js",
+  "main": "lib/index.js",
+  "browser": {
+    "./lib/node.js": "./lib/browser.js"
+  },
   "dependencies": {
     "babel-core": "7.0.0-beta.0",
     "core-js": "^2.4.0",

packages/babel-register/src/browser.js

@@ -1,3 +1,5 @@
 // required to safely use babel/register within a browserify codebase
 
-export default function() {}
+export default function register() {}
+
+export function revert() {}

packages/babel-register/src/index.js

@@ -0,0 +1,15 @@
+/**
+ * This file wraps the compiled ES6 module implementation of register so
+ * that it can be used both from a standard CommonJS environment, and also
+ * from a compiled Babel import.
+ */
+
+exports = module.exports = function(...args) {
+  return register(...args);
+};
+exports.__esModule = true;
+
+const node = require("./node");
+const register = node.default;
+
+Object.assign(exports, node);