Webpack compilation doesn't stop on every semantic error #1066

Environment
CLI: @next
Plugin(s): nativescript-dev-webpack@next

To Reproduce
First scenario:

1. tns create app --ng

2. npm i nativescript-dev-webpack@next --save-dev --save-exact

3. node_modules/.bin/update-ns-webpack --deps --configs

4. tns run ios

5. in app.module.ts change some of the imports to use invalid path

6. the compilation stops on the error which is expected

7. fix the error

8. in item.services.ts change import { Item } to use invalid path
   Result:
   ERROR in src/app/item/item.service.ts(3,22): error TS2307: Cannot find module './items'. but the compilation doesn't stop as expected.

Second scenario:
9. In the same app fix the previous error
10. in app.module.ts change something in the declarations: section
Result: No stop on error. The app is deployed and crashes

Additional context
Not reproducible with nativescript-dev-webpack@1.2.1
It is reproducible with run android too