babel详解

https://segmentfault.com/a/1190000019718925

https://babeljs.io/blog/2019/03/19/7.4.0#core-js-3-7646-https-githubcom-babel-babel-pull-7646

https://juejin.im/post/5ce693b45188252db303ff23

https://github.com/zloirock/core-js/blob/master/docs/2019-03-19-core-js-3-babel-and-a-look-into-the-future.md

https://github.com/zloirock/core-js/tree/master#babelruntime

https://juejin.im/post/5d7efbbb6fb9a06b2650c74a

来源：https://www.cnblogs.com/little-ab/p/11952798.html