Revert of [snapshot] full setup delegate should also be able to deserialize. (patchset #2 id:20001 of https://codereview.chromium.org/2840493002/ )

Reason for revert:
prime suspect for https://bugs.chromium.org/p/chromium/issues/detail?id=714976

Original issue's description:
> [snapshot] full setup delegate should also be able to deserialize.
>
> Also move the responsibility of marking builtins as initialized
> to the deserializer.
>
> R=jkummerow@chromium.org
>
> Review-Url: https://codereview.chromium.org/2840493002
> Cr-Commit-Position: refs/heads/master@{#44802}
> Committed: https://chromium.googlesource.com/v8/v8/+/a2b3a2fbc562584ec298dfe674c97662a125a59e

TBR=jkummerow@chromium.org,yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

BUG=chromium:714976

Review-Url: https://codereview.chromium.org/2841993002
Cr-Commit-Position: refs/heads/master@{#44870}