evolve: use the new rebased changeset to resolve phase-divergence When there is a parent change in phase-divergence, `hg evolve` first rebases the diveregent changeset on parent of public changeset and then continue the resolution of phase-divergence *but* we used to continue with the old divergent changeset rather than the new rebased one. This patch makes sure we use the new rebased changeset to proceed with the resolution. Tests changes shows that it fixes things which were broken earlier.

#require test-repo

  $ checkflake8() {
  >   if ! (which flake8 > /dev/null); then
  >     echo skipped: missing tool: flake8;
  >     exit 80;
  >   fi;
  > };
  $ checkflake8

Copied from Mercurial core (60ee2593a270)

  $ cd "`dirname "$TESTDIR"`"

run flake8 if it exists; if it doesn't, then just skip

  $ hg files -0 'set:(**.py or grep("^#!.*python")) - removed()' \
  > -X hgext3rd/evolve/thirdparty \
  > 2>/dev/null \
  > | xargs -0 flake8