Reland of "[heap] Switch to 500k pages"

Reland of "[heap] Switch to 500k pages" (patchset #1 id:1 of https://codereview.chromium.org/2239323002/ )

Reason for revert:
The underlying issue crbug.com/637279 has been fixed. Let's go again!

Original issue's description:
> Revert of "[heap] Switch to 500k pages" (patchset #11 id:220001 of https://codereview.chromium.org/2232653003/ )
> 
> Reason for revert:
> Breaks benchmark with --turbo on avx2
> 
> https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20avx2/builds/9895
> 
> Original issue's description:
> > Reland of "[heap] Switch to 500k pages"
> >
> > Decrease regular heap object size to 400k. In a follow up, we can now get rid of
> > the new space border page while keeping the 1M minimum new space size.
> >
> > BUG=chromium:636331
> >
> > This reverts commit 555c961990088d545e2b475da3872bd63fa27569.
> >
> > Committed: https://crrev.com/20e2ea80e169e85c5b8231adc02901fb6c989609
> > Cr-Commit-Position: refs/heads/master@{#38608}
> 
> TBR=hpayer@chromium.org,yangguo@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:636331
> 
> Committed: https://crrev.com/1617043c1093870d67eede7828467cc3b77ba9fb
> Cr-Commit-Position: refs/heads/master@{#38613}

TBR=hpayer@chromium.org,yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:636331

[Michael Lippautz, 2016-08-25 14:53:39]

The CQ bit was checked by mlippautz@chromium.org

[Michael Lippautz, 2016-08-25 14:53:40]

Created Reland of "[heap] Switch to 500k pages"

[commit-bot: I haz the power, 2016-08-25 14:53:55]

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, 2016-08-25 14:55:00]

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

[commit-bot: I haz the power, 2016-08-25 14:55:01]

Try jobs failed on following builders:
  v8_linux_dbg_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg_ng/builds/11619)
  v8_presubmit on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/22616)

[Michael Lippautz, 2016-08-25 14:58:06]

Description was changed from

==========
Reland of "[heap] Switch to 500k pages" (patchset #1 id:1 of
https://codereview.chromium.org/2239323002/ )

Reason for revert:
The underlying issue crbug.com/637279 has been fixed. Let's go again!

Original issue's description:
> Revert of "[heap] Switch to 500k pages" (patchset #11 id:220001 of
https://codereview.chromium.org/2232653003/ )
> 
> Reason for revert:
> Breaks benchmark with --turbo on avx2
> 
>
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20avx2/build...
> 
> Original issue's description:
> > Reland of "[heap] Switch to 500k pages"
> >
> > Decrease regular heap object size to 400k. In a follow up, we can now get
rid of
> > the new space border page while keeping the 1M minimum new space size.
> >
> > BUG=chromium:636331
> >
> > This reverts commit 555c961990088d545e2b475da3872bd63fa27569.
> >
> > Committed: https://crrev.com/20e2ea80e169e85c5b8231adc02901fb6c989609
> > Cr-Commit-Position: refs/heads/master@{#38608}
> 
> TBR=hpayer@chromium.org,yangguo@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:636331
> 
> Committed: https://crrev.com/1617043c1093870d67eede7828467cc3b77ba9fb
> Cr-Commit-Position: refs/heads/master@{#38613}

TBR=hpayer@chromium.org,yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:636331
==========

to

==========
Reland of "[heap] Switch to 500k pages" (patchset #1 id:1 of
https://codereview.chromium.org/2239323002/ )

Reason for revert:
The underlying issue crbug.com/637279 has been fixed. Let's go again!

Original issue's description:
> Revert of "[heap] Switch to 500k pages" (patchset #11 id:220001 of
https://codereview.chromium.org/2232653003/ )
> 
> Reason for revert:
> Breaks benchmark with --turbo on avx2
> 
>
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20avx2/build...
> 
> Original issue's description:
> > Reland of "[heap] Switch to 500k pages"
> >
> > Decrease regular heap object size to 400k. In a follow up, we can now get
rid of
> > the new space border page while keeping the 1M minimum new space size.
> >
> > BUG=chromium:636331
> >
> > This reverts commit 555c961990088d545e2b475da3872bd63fa27569.
> >
> > Committed: https://crrev.com/20e2ea80e169e85c5b8231adc02901fb6c989609
> > Cr-Commit-Position: refs/heads/master@{#38608}
> 
> TBR=hpayer@chromium.org,yangguo@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:636331
> 
> Committed: https://crrev.com/1617043c1093870d67eede7828467cc3b77ba9fb
> Cr-Commit-Position: refs/heads/master@{#38613}

TBR=hpayer@chromium.org,yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:636331
==========