Remove sep(Left|Right)Snap as they were never read from

Bug: v8:7327
Change-Id: Id09fa0ec606a75d40cc946b354bc1a260f3b68ac
Notry: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1928855
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65100}