Previous version was https://chromium-review.googlesource.com/502808

BUG=v8:5402

Change-Id: If327f4d7884577b7e5e6159372bf28a80cd21e51
Reviewed-on: https://chromium-review.googlesource.com/506073
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45369}

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}

BUG=v8:5402

Change-Id: I64fae0a0271eb0f1b71f4ec5d9bd5d22deb1cf59
Reviewed-on: https://chromium-review.googlesource.com/502808Reviewed-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}

That way, we don't need to create a context-less constructor function.
Instead, we use the constructor_or_backpointer (or null) field, and
rename it to constructor_or_fti_or_backpointer so nobody is confused.

Note that technically, we still have JSFunctions without contexts, as
they're temporarily created in the deoptimizer.

BUG=v8:6084
R=dcheng@chromium.org,bmeurer@chromium.org,verwaest@chromium.org

Change-Id: I084f052533c317f2cbfb9c35e1acf40263c6257b
Reviewed-on: https://chromium-review.googlesource.com/454636
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43834}

This CL includes runtime and IC parts of the tracking. It is controlled by
compile-time flag FLAG_constant_field_tracking and currently disabled.

Transition from kConst to kMutable still involves map deprecation.

BUG=v8:5495

Review-Url: https://codereview.chromium.org/2598543003
Cr-Commit-Position: refs/heads/master@{#43081}

Currently PropertyConstness is still in sync with PropertyLocation.

BUG=v8:5495

Review-Url: https://codereview.chromium.org/2591233002
Cr-Commit-Position: refs/heads/master@{#42497}

... and rename [Copy]GeneralizeAllRepresentations() -> [Copy]GeneralizeAllFields().

BUG=v8:5495

Review-Url: https://codereview.chromium.org/2632373002
Cr-Commit-Position: refs/heads/master@{#42418}

... including property reconfiguring, elements kind change and migration
of a map to an up-to-date non-deprecated version.

BUG=v8:5495

Review-Url: https://codereview.chromium.org/2601643002
Cr-Commit-Position: refs/heads/master@{#42177}