fix Circle windows build (2)
fix Circle windows build (2)

Summary: Pull Request resolved: https://github.com/facebook/flow/pull/8573

Reviewed By: Hans-Halverson

Differential Revision: D25983897

fbshipit-source-id: 2b5619ac7babba8742fe8144a0ceb6d185c55b67

facebook/flow,mroch/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,facebook/flow