Don't set signal handlers on Windows
Don't set signal handlers on Windows

Summary: Windows doesn't have `sigaction`, so don't try to use it.

Reviewed By: yfeldblum

Differential Revision: D8049407

fbshipit-source-id: f9120eca82ce422607643e9977ad73c418208ffe

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift