Summary:
There was a fix around folly::dynamic constructor that will be needed for Fabric work. This was done in 94e964976c (diff-7d1cb97d222ba0c863ea8a8e43b2ee2b) and luckily the release 1 month after the Folly version we used in RN already had the fix, so that we don't need to upgrade to the latest folly yet (minimizing breakages).
Tested by:
* running RNTester xcode project (ios)
* running RNTesterPods workspace via cocoapods
* building android via gradle
Reviewed By: shergin
Differential Revision: D7626037
fbshipit-source-id: cb36ba5b91ba131d4e450300bd620db657cfa1e8