Bidirectional phase switching by shortcuts "n", "b".
Improved selection of nodes when they are splitting or raising to a common ancestor.
Fixed minor inconsistencies in some variable names with the project style.
Added name and email to the AUTHORS file for first-time contribution.

Change-Id: I0c903dbf81c3d1d75503004ce412a81aace06a61
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3537008Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79636}