The only piece missing at this point was to serialize the code
objects for the resolve and reject handlers.

Bug: v8:7790
Change-Id: If636f9d74dfc9606cf5f45c4f02dd118fb5d8f00
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1662295
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62215}