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 #189631
doc

00:00:27

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

00:04:23

passed #189630
tests-py2-pure

00:03:11