[v8] Fix uses of deprecated Object::Set/Get in fuchsia tests

Always use the Context variant of Set/Get and check their return values.

Bug: v8:7283
Change-Id: I948a4ef9e5cf7f8ca7b3debd22e968ac33d37b9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1583785
Auto-Submit: Dan Elphick <delphick@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654109}
1 file changed