Fix regexpu-core bundling in @babel/standalone

[nicolo-ribaudo]

Q	A
Fixed Issues?	Fixes #13765
Patch: Bug Fix?
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

I'm not sure how it could work in the past, since Node.js loads the CJS version of the plugin and we only patched the ESM version.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/48734/

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 794e289:

Sandbox	Source
babel-repl-custom-plugin	Configuration
babel-plugin-multi-config	Configuration

[nicolo-ribaudo]

It works: https://babeljs.io/repl/build/48734/#?browsers=ie%2011&build=&builtIns=false&corejs=false&spec=false&loose=false&code_lz=MYewdgzgLgBAhjAvDA9AHQA4G8AyBTKKPAJwF8UBXIA&debug=false&forceAllTransforms=false&shippedProposals=false&circleciRepo=&evaluate=true&fileSize=false&timeTravel=false&sourceType=module&lineWrap=false&presets=env&prettier=false&targets=&version=7.15.6%2Bpr.13767&externalPlugins=&assumptions=%7B%7D

[JLHwung]

🤔 I am wondering why #13765 was not caught by

babel/packages/babel-standalone/test/babel.js

Line 254 in a27c1b8

Babel.transform("/\\p{L}/u", {

Should we mock the require in this test?

[nicolo-ribaudo]

Should we mock the require in this test?

Ideally I would like to propose a new @rollup/plugin-commonjs option that stops the final bundle from actually containing a require() call. Many people test their bundles in Node.js where require should be available, and then run them in browsers.