tests/test-revert-flags.t

tests: demonstrate a problem with renames on the p2 side of a conversion

I think this is related to the octopus merge being sloppy, and that's having a
cascading affect on the fixup merge.  If this change is made on p1 (specifically
with the 'Added parent file' commit), the failure doesn't occur.

The file modification with the rename doesn't seem to be necessary, but it's
what's happening in a production repo where I first noticed, so I left it.  This
is an example of the manifest divergence I'd been seeing, which wasn't fixed by
Yuya's recent changes.  This is separate from the changelog divergence I was
also seeing[1].  Probably nobody cares about bzr anymore, but this will also
affect git, since the octopus fixup code is in the hg sink.

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-August/120473.html

#require execbit

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ chmod 644 foo
  $ hg ci -qAm '644'

  $ chmod 755 foo
  $ hg ci -qAm '755'

reverting to rev 0

  $ hg revert -a -r 0
  reverting foo
  $ hg st
  M foo
  $ hg diff --git
  diff --git a/foo b/foo
  old mode 100755
  new mode 100644

  $ cd ..