- Trigger serialization for more objects, such as some root maps.
- Serialize more data for certain object kinds.
- Add macros for convenience.
- Mark a few functions as const.

R=jarin@chromium.org
Bug: v8:7790

Change-Id: Id39b97e93728c0b3d87d9546bdf68abd04496c05
Reviewed-on: https://chromium-review.googlesource.com/1158572Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54923}