Similar to other stack references they don't need to be scanned on incremental
marking start.

Bug: chromium:1046277
Change-Id: I9fb3ee768df0288b5a61f09e680e321a8cb7b895
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2030915Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66080}