This is a first bulk of changes.

BUG=v8:6116

Change-Id: I9308129bd032c0bf5b60c8e0413ee2cb710891ea
Reviewed-on: https://chromium-review.googlesource.com/456556
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43930}

This is in preparation for linking the former only into mksnapshot.
Just shuffling code around, no changes in functionality.

BUG=v8:6055

Review-Url: https://codereview.chromium.org/2752143004
Cr-Commit-Position: refs/heads/master@{#43858}