Inconsistent displayName configuration for context Consumer/Provider

[nathanmarks]

Due to this change after the original PR:

c2db8dd

This is now needed to set the displayName for both as for Consumer we do not look up the displayName on _context like we do for Provider:

TestContext.displayName = 'TestContext';
TestContext.Consumer.displayName = 'TestContext';

Was this intentional or can I submit a PR to fix it?

[nathanmarks]

This also needs to be fixed for TS usage: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/react/index.d.ts#L307

[bvaughn]

This seems to have broken as a result of changes made to context in React v16.6. (Our regression test harness shows it working for versions 16.3-16.5)

The React team doesn't maintain or contribute to the DefinitelyTyped repo, so you'll probably want to file a separate issue (or PR) for any changes needed there.