Reland "[heap] Turn on parallel compaction"

Reland "[heap] Turn on parallel compaction"

BUG=chromium:524425
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg;tryserver.v8:v8_linux_gc_stress_dbg;tryserver.v8:v8_mac_gc_stress_dbg;tryserver.v8:v8_linux64_msan_rel;tryserver.v8:v8_linux64_tsan_rel

Committed: https://crrev.com/973377e5d651970b57b92cf74f0bb32740b5ce0a
Cr-Commit-Position: refs/heads/master@{#32097}

[Hannes Payer (out of office), 2015-11-18 17:19:34]

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

[Hannes Payer (out of office), 2015-11-18 17:19:34]

lgtm

[Michael Lippautz, 2015-11-18 17:36:01]

The CQ bit was checked by mlippautz@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-11-18 17:36:06]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1461693002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1461693002/1

[commit-bot: I haz the power, 2015-11-18 18:16:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-18 18:16:38]

Dry run: This issue passed the CQ dry run.

[Michael Lippautz, 2015-11-18 20:03:54]

The CQ bit was checked by mlippautz@chromium.org

[commit-bot: I haz the power, 2015-11-18 20:03:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1461693002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1461693002/1

[commit-bot: I haz the power, 2015-11-18 20:05:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-18 20:05:39]

Patchset 1 (id:??) landed as
https://crrev.com/973377e5d651970b57b92cf74f0bb32740b5ce0a
Cr-Commit-Position: refs/heads/master@{#32097}