test-compat: merge mercurial-4.7 into mercurial-4.6

# no-check-commit

--HG--
branch : mercurial-4.6
4 jobs for topic/mercurial-4.6/release-prep in 5 minutes and 28 seconds (queued for 3 minutes and 29 seconds)
Status Name Job ID Coverage
  Test
passed doc #160672

00:00:31

manual pytype #160669
allowed to fail manual
passed tests-py2-cext #160670

00:05:28

passed tests-py2-pure #160671

00:02:59