Summary:
D38460203 (https://github.com/facebook/react-native/commit/e6ef0836c132d6b798e2ff1fc1e1a66c7e238e0b) was reverted because it broke OSS, the root cause is that OSS doesn't have MapBuffer module.
Fixed the issue in this diff by moving MapBuffer usage to fb internal class (FBReactModule) and will re-land.
Changelog:
[iOS][Changed] Replace Folly with MapBuffer for passing js error data
Reviewed By: sammy-SC
Differential Revision: D39210957
fbshipit-source-id: dda0e8c55dbd13bc96310e10a3b09ea53978e8bc