... to MaybeHandle<Map> and add TransitionsAccessor::FindTransitionToDataProperty()
which will be used in follow-up CLs.

Bug: v8:7310
Change-Id: I98cc4fe16dc1ef335885101aa457f27c90ecf1a4
Reviewed-on: https://chromium-review.googlesource.com/968222Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52018}