title: CallerMemberName is empty if used from base class constructor and not initialized
body: <p>I have two classes like this:</p>
  <pre><code>public class test1: BaseClass
  {
      public test1() : base()
      {
      }
  ...
  
  public class BaseClass
  {
      public BaseClass(
          [CallerMemberName]string membername =&quot;&quot;,
          [CallerFilePath] string path = &quot;&quot;)
      {
          var sf = new System.Diagnostics.StackTrace(1).GetFrame(0);
      }
  </code></pre>
  <p>If I specify <code>test1</code> ctor with call to base - I get <code>membername</code> and <code>path</code> initialized properly, but if not - compiler generates default constructor call, and <code>membername</code> and <code>path</code> are both empty.</p>
  <p>Is this a bug or a feature ?</p>
  <p>(Visual Studio 2019 16.11.8, net core 3.1 or net 5.0).</p>