as part of the continuing quest to get rid of Object*/Object**.
This is a fairly mechanical replacement of Object**/MaybeObject** with
wrapper objects carrying the same data. No change in behavior is intended.
Overloaded operators are provided to minimize code churn.

Bug: v8:3770
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I76cee82b8bf2dd80a1b66f09dd2bb2b65038eeb7
Reviewed-on: https://chromium-review.googlesource.com/c/1287889
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56920}