[heap] Reland "Make non-atomic markbit operations consistent with atomic ones."

[heap] Reland "Make non-atomic markbit operations consistent with atomic ones."

Now non-atomic color transition operations return a boolean indicating
whether the transition succeeded or not.

This allows to replace color check and transition operations with a
single transition operation. For example:

if (IsWhite(object)) {
  WhiteToBlack(object);
  Foo();
}

becomes

if (WhiteToBlack(object)) {
  Foo();
}

BUG=chromium:694255
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng

Review-Url: https://codereview.chromium.org/2860323003
Cr-Commit-Position: refs/heads/master@{#45123}
Committed: https://chromium.googlesource.com/v8/v8/+/c0a65cd295301f334e2bbfcce46a937cd708beec

[ulan, 2017-05-05 09:14:40]

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

[ulan, 2017-05-05 09:14:40]

ptal, the fix is in the diff between patch set 1 and 2.

[Michael Lippautz, 2017-05-05 09:16:09]

lgtm

[ulan, 2017-05-05 09:16:19]

The CQ bit was checked by ulan@chromium.org

[commit-bot: I haz the power, 2017-05-05 09:16:22]

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 10:16:01]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1493975779863510,
"parent_rev": "56352067f2b7311725763b1b568b153947bf423a", "commit_rev":
"c0a65cd295301f334e2bbfcce46a937cd708beec"}

[commit-bot: I haz the power, 2017-05-05 10:16:07]

Description was changed from

==========
[heap] Reland "Make non-atomic markbit operations consistent with atomic ones."

Now non-atomic color transition operations return a boolean indicating
whether the transition succeeded or not.

This allows to replace color check and transition operations with a
single transition operation. For example:

if (IsWhite(object)) {
  WhiteToBlack(object);
  Foo();
}

becomes

if (WhiteToBlack(object)) {
  Foo();
}

BUG=chromium:694255

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng
==========

to

==========
[heap] Reland "Make non-atomic markbit operations consistent with atomic ones."

Now non-atomic color transition operations return a boolean indicating
whether the transition succeeded or not.

This allows to replace color check and transition operations with a
single transition operation. For example:

if (IsWhite(object)) {
  WhiteToBlack(object);
  Foo();
}

becomes

if (WhiteToBlack(object)) {
  Foo();
}

BUG=chromium:694255

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_rel_ng

Review-Url: https://codereview.chromium.org/2860323003
Cr-Commit-Position: refs/heads/master@{#45123}
Committed:
https://chromium.googlesource.com/v8/v8/+/c0a65cd295301f334e2bbfcce46a937cd70...
==========

[commit-bot: I haz the power, 2017-05-05 10:16:08]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/c0a65cd295301f334e2bbfcce46a937cd70...

[ulan, 2017-05-05 11:17:04]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/2863953002/ by ulan@chromium.org.

The reason for reverting is: box2d failures on buildbot.