Summary:
@public
If some prop has `std::vector` type, it possible that on JS side we want to pass just one element of the array.
And in this case we sometimes drop array initialization (`[]`) part, so instead of passing `[{x:1, y:1}]` we pass `{x:1, y:1}`.
This diff adds support for that.
Reviewed By: mdvacca
Differential Revision: D8526572
fbshipit-source-id: 33d4369ac48cac3eb1c534f477d8259e76e0c547