Summary:
**This is a manual React sync to replace Haste names with paths so that the removal of Haste is not blocked on a normal React sync. This is a one-time special case; in the future, React will generate renderers that use paths instead of Haste.**
This commit uses the same base commit of React that's currently in RN (React ec6691a68716bc59291746fc62f374a56fb435c9) plus a commit in the React repo that removes Haste-style imports from the renderer (61f62246c8cfb76a4a19d1661eeaa5822ec37b36) and a commit to make the shims import from `implementations` (https://github.com/facebook/react/pull/15786).
I built React in the React repo with `yarn build` and copied over the `oss` directory into one called `implementations` and removed the `*.fb.js` files.
## Changelog
[General] [Changed] - Sync React with Haste-style imports rewritten to use path-based imports instead
Pull Request resolved: https://github.com/facebook/react-native/pull/25100
Reviewed By: yungsters
Differential Revision: D15575646
Pulled By: cpojer
fbshipit-source-id: adf25f9826b71729043b65ba1afd20d14d8c19c4
James Ide
Brian Vaughn
Héctor Ramos