tests: suppress output from write() Otherwise it is printed and the test fails with tons of output on Python 3. Differential Revision: https://phab.mercurial-scm.org/D6918

tests: look for additional pip warning variant The wording has been tweaked in new versions of pip. Differential Revision: https://phab.mercurial-scm.org/D6909

tests: use test harness `hg` in test-hghave.t This prevents the sub test harness from rebuilding Mercurial. It shaves ~30s from the test wall time on my machine. Differential Revision: https://phab.mercurial-scm.org/D6908

synthrepo: use pycompat.xrange This silences some test-check-pyflakes.t warnings on Python 3. Differential Revision: https://phab.mercurial-scm.org/D6907

perf: fix perfhelper-pathcopies without --stats Some conditional were missing.

upgrade: also register copied `.d` files to fncache Oops, we forgot to register data file when blanky copying revlog. Now that we are actually copying these `.d` files, we should also register them. Differential Revision: https://phab.mercurial-scm.org/D6905

upgrade: fix handling of `.d` data file The test did not used any `.d` file. So of course, their handling was broken (for vfs encoding reason again). We fix the issue and update the test. Note that some fncache issue remains with `.d` file. It will be taken care of in the next changesets. Differential Revision: https://phab.mercurial-scm.org/D6904

upgrade: also copy data file Differential Revision: https://phab.mercurial-scm.org/D6903