I18nPluralPipe can actually accept `null` and `undefined` (which are
convenient for composing it with the async pipe), but it is currently
typed to only accept `number`.
PR Close#37447
After this, neither @angular/compiler nor @angular/comnpiler-cli depend
on @angular/core.
This add a duplication of some interfaces and enums which is stored
in @angular/compiler/src/core.ts
BREAKING CHANGE:
- `@angular/platform-server` now additionally depends on
`@angular/platform-browser-dynamic` as a peer dependency.
PR Close#18683