Do not call -[FBProcessIO teardown] for resolution of signal, exitCode, completed futures.
Do not call -[FBProcessIO teardown] for resolution of signal, exitCode, completed futures.

Summary:
The first future to resolve when the task completes in some fashion is `-[FBTask statLoc]`. It will always resolve successfully. The futures for `-[FBTask completed]`, `-[FBTask exitCode]` and `-[FBTask signal]`, all have different semantics.

However, the resolution of these futures should wait until **after* `-[FBTask statLoc]` has finished. The reason for doing this is that we do not want these futures to resolve **until IO teardown has finished**.

Reviewed By: jbardini

Differential Revision: D29330797

fbshipit-source-id: e64370c583c9a9f52e224bad7ab632a1911f5985

facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl