This just adds calls to SerializePrototype right before we access the
serialized prototype. Eventually we need to do this earlier.

Bug: v8:7790, chromium:899115
Change-Id: I597e95f5f6df8aae608ee295fe9550e7c2a45e6d
Reviewed-on: https://chromium-review.googlesource.com/c/1301475Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57034}