How to get component instance by a component name?

[kachurunus]

I've updated from 6.1.4 to 9.x and lost the ability to get a component instance by its name. I need this because I register all my components globally and always use them by name. I also have what you might call a "proxy" component in another framework (actually, it's riot3), and I call this proxy component like this:

<proxy component="my-fancy-riot-component" some-prop="123">Yes, I will need this slot too.</proxy>

So, inside this proxy component, I need to get the component implementation to mount it:

const component = riot.__.globals.COMPONENTS_IMPLEMENTATION_MAP.get(componentName);
const slots = this.showSlot ? [{
    id: 'default',
    html: '<mark class="default"></mark>'
}] : [];

this.component = component({ props, slots }).mount(this.root, this);

Before, I got it through riot.__.globals, and now I've lost this ability. I can't just use the riot.mount method because it doesn't support slots (by the way, mountComponent(element, initialProps, componentName, slots) in the riot source code is private and is never called with the 4th argument).

I have two ideas:

Add a get method to the API to get the component implementation by name.
Export the core mountComponent method.

[GianlucaGuarini]

Thank you @kachurunus for your PR. Your patch was included in riot@9.1.6