Merge branch 'js/rebase-cleanup'

Update supporting parts of "git rebase" to remove code that should no longer be used. * js/rebase-cleanup: rebase: fold git-rebase--common into the -p backend sequencer: the `am` and `rebase--interactive` scripts are gone .gitignore: there is no longer a built-in `git-rebase--interactive` t3400: stop referring to the scripted rebase Drop unused git-rebase--am.sh