What problem does this feature solve?

能否类似于uniapp 的easycom模式，使vue组件无需引入即可使用组件;这个在引入一个ui库的时候，很方便使用。 https://uniapp.dcloud.io/collocation/pages?id=easycom

What does the proposed API look like?

简化对组件的引入，使得代码更简洁。写代码的人不用手动按需引入，由编译器自动识别并引入组件，从而简化组件的使用。

This will be a awesome feature. I opened a rfc: https://github.com/vuejs/rfcs/issues/237

This is something to be implemented as a babel transform or similar like https://github.com/nuxt/components

Note: open issues in English so everybody can participate