Drive-by cleanup: improve prining of lists

Bug: v8:7793
Change-Id: I84d2d5c64ae3cb564acf53d93ea4f12a829b787d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1967328Reviewed-by: Joshua Litt <joshualitt@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65451}