**Do you want to request a _feature_ or report a _bug_?**
Enhancement

**What is the current behavior?**
Element type checker is not as informative as the other ones.

**What is the expected behavior?**
It would be nice to provide the actual type of the prop passed similarly to other type checkers. I.e., instead of 

> Invalid prop `Prop` supplied to `Component`, expected a single ReactElement.

say

> Invalid prop `Prop` of type `type` supplied to `Component`, expected a single ReactElement.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Seeing this on 15.2.1 but I think it's also applicable to previous versions.

I know the general intention is to move away from prop types, but if there isn't a specific reason for the current behavior I can look into making this more pretty.

iterable.entries = iterable['@@iterator'];
      typeCheckPass(PropTypes.node, iterable);
    });
    it('should not warn for null/undefined if not required', function() {
      typeCheckPass(PropTypes.node, null);
      typeCheckPass(PropTypes.node, undefined);
    });
    it('should warn for missing required values', function() {
      typeCheckFail(
        PropTypes.node.isRequired,
        null,
        'Required prop `testProp` was not specified in `testComponent`.'
      );
      typeCheckFail(
        PropTypes.node.isRequired,
        undefined,
        'Required prop `testProp` was not specified in `testComponent`.'
      );
    });
    it('should accept empty array for required props', function() {
      typeCheckPass(PropTypes.node.isRequired, []);
    });
    it('should warn if called manually in development', function() {
      spyOn(console, 'error');
      expectWarningInDevelopment(PropTypes.node, 'node');
      expectWarningInDevelopment(PropTypes.node, {});
      expectWarningInDevelopment(PropTypes.node.isRequired, 'node');
      expectWarningInDevelopment(PropTypes.node.isRequired, undefined);
      expectWarningInDevelopment(PropTypes.node.isRequired, undefined);
    });