tests/test-locale.t

debugdiscovery: use `get_unique_pull_path`

Lets move this code to the new API.

Differential Revision: https://phab.mercurial-scm.org/D10426

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