Please forgive me if this appears more like a rant than a feature request, but I have searched and can't find any explanation for why some error messages are displayed without any `displayName` from the component responsible - and this is driving me insane.

_Every_ component in my project has an explicit `displayName` specified.  I do this for debugging.

I am rendering a bunch of immutable props.  I changed one of the prop types from a `List` to a `Map` and I see:

> Warning: Using Maps as children is not yet fully supported. It is an experimental feature that might be removed. Convert it to a sequence / iterable of keyed ReactElements instead.

Obviously I missed something, which could be easily fixed if I knew _where_ it was - even just the component's name.

This message is not only frustrating, but it's taunting "I know where the problem is but I won't tell you!"-feel makes it infuriating.  Looking at the stacktrace behind it is useless as well because it's, as usual, a never-ending list of React function calls with no mention of any of my source files.

I have spent countless time hunting down errors like this that would have taken only moments if I knew the name of the component responsible.  It would be _infinitely more helpful_ if the `displayName` field appeared in more debug output.

/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @emails react-core
 */
'use strict';
describe('traverseAllChildren', function() {
  var traverseAllChildren;
  var React;
  var ReactFragment;
  beforeEach(function() {
    jest.resetModuleRegistry();
    traverseAllChildren = require('traverseAllChildren');
    React = require('React');
    ReactFragment = require('ReactFragment');
  });
  function frag(obj) {
    return ReactFragment.create(obj);
  }
  it('should support identity for simple', function() {
    var traverseContext = [];
    var traverseFn =