How to use a custom ElementSchemaRegistry in tests?

[CSchulz]

I have upgraded to Angular 9 and enabled Ivy. I am wondering why my tests fails with complaining about unknown elements:

core.js:14377 'content-block' is not a known element:

1. If 'content-block' is an Angular component, then verify that it is part of this module.

2. If 'content-block' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.

Before Angular 9 we used a custom ElementSchemaRegistry to check the tag names, but it seems this feature is missing with Ivy:

https://github.com/angular/angular/blob/d543b13e5c644fe11f90ca885cfb81b7de2ca855/packages/core/src/render3/instructions/element.ts#L174-L213

Is any equivalent solution available or planned?