rust-dirstate-status: use fast-path even with fsmonitor and sparse extensions When I initially ran the tests on my series, there were test failures related to those extensions. Now that the initial series has landed, I felt like going back to those issues because people with performance issues will often want to use fsmonitor and sparse. Either because of flaky tests or because the series has changed so much, I can't seem to reproduce these issues... let's widen the scope of the fast-path. Differential Revision: https://phab.mercurial-scm.org/D7128