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.

);
    return 1;
  }
  var child;
  var nextName;
  var subtreeCount = 0; 
  var nextNamePrefix = nameSoFar === '' ? SEPARATOR : nameSoFar + SUBSEPARATOR;
  if (Array.isArray(children)) {
    for (var i = 0; i < children.length; i++) {
      child = children[i];
      nextName = nextNamePrefix + getComponentKey(child, i);
      subtreeCount += traverseAllChildrenImpl(
        child,
        nextName,
        callback,
        traverseContext
      );
    }
  } else {
    var iteratorFn = getIteratorFn(children);
    if (iteratorFn) {
      var iterator = iteratorFn.call(children);
      var step;
      if (iteratorFn !== children.entries) {
        var ii = 0;
        while (!(step = iterator.next()).done) {
          child = step.value;
          nextName = nextNamePrefix + getComponentKey(child, ii++);
          subtreeCount += traverseAllChildrenImpl(
            child,