[heap] Use shared markbits in the concurrent marker.

[heap] Use shared markbits in the concurrent marker.

The concurrent marker now colors objects grey and black using
the atomic markbit operations.

The heap visitor is changed in two ways:
1) It iterates the map pointer of each object.
2) It guards object visitation with a predicate, which is overridden
in the concurrent marker with the result of GreyToBlack transition.


BUG=chromium:694255
Review-Url: https://codereview.chromium.org/2855003004
Cr-Commit-Position: refs/heads/master@{#45099}
Committed: https://chromium.googlesource.com/v8/v8/+/b0db0541ee0f9b749cbaefc9d92b61293234e951

[ulan, 2017-05-03 20:04:52]

Description was changed from

==========
[heap] Use shared markbits in concurrent marker.

BUG=chromium:694255
==========

to

==========
[heap] Use shared markbits in the concurrent marker.

The concurrent marker now colors objects grey and black using
the atomic markbit operations.

The heap visitor is changed in two ways:
1) It iterates the map pointer of each object.
2) It guards object visitation with a predicate, which is overridden
in the concurrent marker with the result of GreyToBlack transition.


BUG=chromium:694255
==========

[ulan, 2017-05-03 20:06:03]

ulan@chromium.org changed reviewers:
+ hpayer@chromium.org

[ulan, 2017-05-03 20:06:04]

ptal

[Hannes Payer (out of office), 2017-05-04 11:31:54]

lgtm

[ulan, 2017-05-04 13:21:52]

The CQ bit was checked by ulan@chromium.org

[ulan, 2017-05-04 13:21:53]

The patchset sent to the CQ was uploaded after l-g-t-m from hpayer@chromium.org
Link to the patchset: https://codereview.chromium.org/2855003004/#ps60001
(title: "rebase")

[commit-bot: I haz the power, 2017-05-04 13:21:55]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-04 13:55:45]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1493904112958640,
"parent_rev": "3a47312226747e9297ed72474b481ec5bcf884df", "commit_rev":
"b0db0541ee0f9b749cbaefc9d92b61293234e951"}

[commit-bot: I haz the power, 2017-05-04 13:55:52]

Description was changed from

==========
[heap] Use shared markbits in the concurrent marker.

The concurrent marker now colors objects grey and black using
the atomic markbit operations.

The heap visitor is changed in two ways:
1) It iterates the map pointer of each object.
2) It guards object visitation with a predicate, which is overridden
in the concurrent marker with the result of GreyToBlack transition.


BUG=chromium:694255
==========

to

==========
[heap] Use shared markbits in the concurrent marker.

The concurrent marker now colors objects grey and black using
the atomic markbit operations.

The heap visitor is changed in two ways:
1) It iterates the map pointer of each object.
2) It guards object visitation with a predicate, which is overridden
in the concurrent marker with the result of GreyToBlack transition.


BUG=chromium:694255

Review-Url: https://codereview.chromium.org/2855003004
Cr-Commit-Position: refs/heads/master@{#45099}
Committed:
https://chromium.googlesource.com/v8/v8/+/b0db0541ee0f9b749cbaefc9d92b6129323...
==========

[commit-bot: I haz the power, 2017-05-04 13:55:53]

Committed patchset #4 (id:60001) as
https://chromium.googlesource.com/v8/v8/+/b0db0541ee0f9b749cbaefc9d92b6129323...