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

--HG--
branch : mercurial-4.6
4 jobs for topic/mercurial-4.6/release-prep in 4 minutes and 23 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed doc #189631

00:00:27

manual pytype #189628
allowed to fail manual
passed tests-py2-cext #189629

00:04:23

passed tests-py2-pure #189630

00:03:11