[heap] Reland "Use shared markbits in the concurrent marker."

[heap] Reland "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
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng

Review-Url: https://codereview.chromium.org/2866473003
Cr-Commit-Position: refs/heads/master@{#45144}
Committed: https://chromium.googlesource.com/v8/v8/+/1b064d9cd015bfa8878e190243ca7cbdfe69482b

[ulan, 2017-05-05 09:41:23]

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

[ulan, 2017-05-05 09:41:24]

Relanding without any changes from the original CL because the CL was revert due
to dependency with another CL.

[Michael Lippautz, 2017-05-05 09:45:03]

lgtm

[ulan, 2017-05-05 15:00:57]

The CQ bit was checked by ulan@chromium.org

[ulan, 2017-05-05 15:00:58]

The patchset sent to the CQ was uploaded after l-g-t-m from
mlippautz@chromium.org
Link to the patchset: https://codereview.chromium.org/2866473003/#ps20001
(title: "rebase")

[commit-bot: I haz the power, 2017-05-05 15:01:00]

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, 2017-05-05 17:41:45]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1493996457957170,
"parent_rev": "2fd1afc0c8128148b74b3d9ff7b39c084c7dd90b", "commit_rev":
"1b064d9cd015bfa8878e190243ca7cbdfe69482b"}

[commit-bot: I haz the power, 2017-05-05 17:41:54]

Description was changed from

==========
[heap] Reland "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
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng
==========

to

==========
[heap] Reland "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
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng

Review-Url: https://codereview.chromium.org/2866473003
Cr-Commit-Position: refs/heads/master@{#45144}
Committed:
https://chromium.googlesource.com/v8/v8/+/1b064d9cd015bfa8878e190243ca7cbdfe6...
==========

[commit-bot: I haz the power, 2017-05-05 17:41:55]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/1b064d9cd015bfa8878e190243ca7cbdfe6...