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.

children,
  nameSoFar,
  callback,
  traverseContext
) {
  var type = typeof children;
  if (type === 'undefined' || type === 'boolean') {
    
    children = null;
  }
  if (children === null ||
      type === 'string' ||
      type === 'number' ||
      ReactElement.isValidElement(children)) {
    callback(
      traverseContext,
      children,
      
      
      nameSoFar === '' ? SEPARATOR + getComponentKey(children, 0) : nameSoFar