title: reactive forms validation not working on IE 11
body: <p>I have reactive form set up as follows (HTML) - </p>
  
  <pre><code>&lt;form [formGroup]="myForm" novalidate autocomplete="off"&gt;
    &lt;input type="text"
           class="form-control" id="name"
           placeholder="enter name"
           formControlName="name"/&gt;
    &lt;div class="alert-danger"&gt;
      {{myForm.get('name').valid}} 
      {{myForm.get('name').pristine}}
   &lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>For some reason, when I interact with the control, on Internet Explorer 11, the valid and pristine values are not updated.
  In Chrome/FF, it is working as expected - form control state is changed.</p>
  
  <p>Has anyone faced similar problem before?</p>