This adds a guard for a forwarding address in the debug mode checks
of FixStaleLeftTrimmedHandlesVisitor::FixHandle.

Bug: chromium:1146601
Change-Id: I6681352a91177c1d138a409d17e5d170bd43f11b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2526389
Auto-Submit: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71055}