title: Why are methods not valid constructors?
body: <p>Regardless of intent, it's unclear to me why one is valid and other other is not. If someone could point to the relevant part of the language spec, that would be especially helpful.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>class Foo {
    bar() {}
  }
  Foo.prototype.baz = function() {};
  
  const f = new Foo();
  
  new f.baz(); // Valid
  new f.bar(); // invalid, throws error</code></pre>
  </div>
  </div>
  </p>