... and use RelocInfo iteration instead of skip-and-unaligned-write sequences.
This is a step towards avoiding unaligned stores via UnalignedSlot.

Various cleanup CLs will follow.

Bug: v8:8794
Change-Id: I62faedfa1c1ababe4b185fa8d7f2c6c1baa5cf79
Reviewed-on: https://chromium-review.googlesource.com/c/1456579
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59443}