@angular/material entry-point causes very slow builds with Ivy

Reproduction

Steps to reproduce:

yarn global add @angular-cli@next
ng new foo --enable-ivy
ng add @angular/material
ng generate @angular/material:nav my-navbar
ng build

Expected Behavior

What behavior were you expecting to see?

ngcc will compile just a handful of entrypoints needed for the navbar. This should take just a few seconds.

Actual Behavior

What behavior did you actually see?

ngcc compiles all entrypoints within the @angular/material package as well as some/all entry-points within @angular/cdk package.

This delays the initial build by as much as 2 minutes.

Environment

• Angular: 8.1.0-next.0
• CDK/Material: 8.0.2
• Browser(s):
• Operating System (e.g. Windows, macOS, Ubuntu):

Proposed solution

• update schematics to use deep secondary entry-points instead of the main entry point import { MatToolbarModule, MatButtonModule, MatSidenavModule, MatIconModule, MatListModule } from '@angular/material';
• execute migration to secondary entry-points and remove the @angular/material entry-point

[Splaktar]

The related deprecation guidelines were discussed in today’s sync.

Deprecation period: When an API or a feature is deprecated, it will still be present in the next two major releases. After that, deprecated APIs and features will be candidates for removal.

Perhaps since these are not changes to the APIs and only changes to the paths of the imports, this may not require 2 majors before removal?

[devversion]

The schematics have been already updated to use the secondary entry-points. For reference: https://github.com/angular/components/commit/b823dbd8b66db47e5f7d0a646020e9f77e87c270