Summary:
The mismatched project output settings were causing
the dyndeps fixup to fail to find any objects and thus none of
the artifacts are populated for posix platforms.

Pull Request resolved: https://github.com/facebook/watchman/pull/808

Test Plan:
The PR published artifacts to:

* https://github.com/facebook/watchman/actions/runs/91617994
* https://github.com/facebook/watchman/actions/runs/91617996
* https://github.com/facebook/watchman/actions/runs/91617997

Reviewed By: simpkins

Differential Revision: D21315090

Pulled By: wez

fbshipit-source-id: 60461809f55e73119f7206e3f392d5b237722f85