title: Is not core-js needed anymore?
body: <p>I've updated an Angular project from version 7 to 8. Everything runs smoothly, schematics did it's job (maybe) and we are Ok (project is even in production). When we're updating Angular CLI, we always generate a new project to see the real differences and learn from them such as new dependencies, configurations, etc.</p>
  
  <p>When generating a new Angular project with Angular CLI 8.0.4, the new app doesn't have <code>core-js</code> as dependency:</p>
  
  <pre><code>"dependencies": {
      "@angular/animations": "~8.0.1",
      "@angular/common": "~8.0.1",
      "@angular/compiler": "~8.0.1",
      "@angular/core": "~8.0.1",
      "@angular/forms": "~8.0.1",
      "@angular/platform-browser": "~8.0.1",
      "@angular/platform-browser-dynamic": "~8.0.1",
      "@angular/router": "~8.0.1",
      "rxjs": "~6.4.0",
      "tslib": "^1.9.0",
      "zone.js": "~0.9.1"
    }
  </code></pre>
  
  <p>Analyzing bundle on built project <code>core-js</code> is not there:
  <a href="https://i.stack.imgur.com/sWN7U.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/sWN7U.jpg" alt="Bundle without core-js"></a>
  On my <em>older</em> project, updated with Angular CLI, <code>core-js</code> is there and is present in the final bundle:</p>
  
  <pre><code>"dependencies": {
      "@angular/animations": "~8.0.3",
      "@angular/cdk": "~8.0.1",
      "@angular/common": "~8.0.3",
      "@angular/compiler": "~8.0.3",
      "@angular/core": "~8.0.3",
      "@angular/forms": "~8.0.3",
      "@angular/platform-browser": "~8.0.3",
      "@angular/platform-browser-dynamic": "~8.0.3",
      "@angular/router": "~8.0.3",
      "@auth0/angular-jwt": "2.1.1",
      "@hackages/ngxerrors": "~8.0.0",
      "@ng-bootstrap/ng-bootstrap": "5.0.0-rc.1",
      "@ngx-loading-bar/core": "~4.2.0",
      "@ngx-loading-bar/http-client": "~4.2.0",
      "@nicky-lenaers/ngx-scroll-to": "~2.0.0",
      "@swimlane/ngx-charts": "~12.0.1",
      "bootstrap": "~4.3.1",
      "core-js": "~2.6.9",
      "d3-scale": "~3.0.0",
      "d3-shape": "~1.3.5",
      "date-fns": "2.0.0-beta.2",
      "ngx-perfect-scrollbar": "~8.0.0",
      "ngx-toastr": "~10.0.4",
      "rxjs": "~6.5.2",
      "tslib": "~1.10.0",
      "xlsx": "~0.14.3",
      "zone.js": "~0.9.1"
    }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/BuZPS.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/BuZPS.jpg" alt="core-js present in final bundle"></a></p>
  
  <p>Why is this behavior? Is it safe to remove <code>core-js</code> as dependency? Does update schematics missing this? When installing <code>npm</code> dependencies on the newest project I get the post-install messages from <code>core-js</code>, but it is not explicitly present in package description. </p>