tests/test-locale.t

dirstate: use `reset_state` in `rebuild` instead of `dropfile`

As `dirstatemap.dropfile` is on its way out.

Differential Revision: https://phab.mercurial-scm.org/D11440

  $ LANG=nonexistent LC_ALL=nonexistent LANGUAGE=nonexistent hg version -q
  Mercurial Distributed SCM (version *) (glob)