tests/test-merge8.t

tests: add tests showing pulling from infinitepush works over wire

The current tests in test-infinitepush-ci.t showed that `hg pull -r <rev>` does
not work. Digging in code, I found that we have logic for pulling from
bundlestore without having client side logic. This patch adds test demonstrating
that pulling from bundlestore works when working over wire.
Pulling from bundlestore when the peer is a localpeer still does not works.

Differential Revision: https://phab.mercurial-scm.org/D3072

Test for changeset ba7c74081861
(update dirstate correctly for non-branchmerge updates)
  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ hg commit -m a
  $ cd ..
  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd a
  $ hg mv a b
  $ hg commit -m move
  $ echo b >> b
  $ hg commit -m b
  $ cd ../b
  $ hg pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets e3c9b40284e1:772b37f1ca37
  (run 'hg update' to get a working copy)
  $ hg update
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cd ..