fix parser tests on Windows CI
fix parser tests on Windows CI

Summary:
Pull Request resolved: https://github.com/facebook/flow/pull/8947

Changelog: [internal]

Reviewed By: SamChou19815

Differential Revision: D41414458

fbshipit-source-id: 4c39195e0acc50f2d768c621ef36f397bc02b256

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