Function move_commits 

pub fn move_commits(
    mut_repo: &mut MutableRepo,
    loc: &MoveCommitsLocation,
    options: &RebaseOptions,
) -> BackendResult<MoveCommitsStats>

Moves loc.target commits from their current location to a new location in the graph.

Commits in target are rebased onto the new parents given by new_parent_ids, while the new_child_ids commits are rebased onto the heads of the commits in targets. This assumes that commits in target and new_child_ids can be rewritten, and there will be no cycles in the resulting graph. Commits in target should be in reverse topological order.