[builtins] Update off-heap-safe list

TBR=yangguo@chromium.org

Bug: v8:6666
Change-Id: I70ba2ecbc259431b571a2e5611494dd7725f2aa6
Reviewed-on: https://chromium-review.googlesource.com/937302Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51567}