This reverts commit 7be0159e.

Reason for revert: Broke node by generating a broken debug-support.cc

Original change's description:
> [objects.h splitting] Move Map and related classes.
> 
> BUG=v8:5402
> 
> Change-Id: I64fae0a0271eb0f1b71f4ec5d9bd5d22deb1cf59
> Reviewed-on: https://chromium-review.googlesource.com/502808
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45305}

TBR=marja@chromium.org,mstarzinger@chromium.org,jarin@chromium.org,ishell@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5402

Change-Id: Ifa65537447eb0a1ef947b9d0dae6f07a8b150968
Reviewed-on: https://chromium-review.googlesource.com/506011Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45307}