[interpreter] Add constant_pool() to BytecodeArray.

[interpreter] Add constant_pool() to BytecodeArray.

Adds a (currently unused) constant_pool() field to BytecodeArray objects.
This field points to a FixedArray object which will be used to hold constants.

The BytecodeArray is now a mixed values object type, with the
kConstantPoolOffset object holding a tagged pointer, but the remainder of the
object holding raw bytes (which could look like tagged pointers but are not).
Modify the BytecodeArray GC visitors to deal with this and test that the
field is migrated properly when evacuated.

BUG=v8:4280
LOG=N

Committed: https://crrev.com/69ce0f4dc79a5606eec03accd81832aaeaa16075
Cr-Commit-Position: refs/heads/master@{#30404}

[rmcilroy, 2015-08-25 23:54:15]

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

[commit-bot: I haz the power, 2015-08-25 23:54:31]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314953004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314953004/1

[commit-bot: I haz the power, 2015-08-26 00:05:05]

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

[commit-bot: I haz the power, 2015-08-26 00:05:05]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/...)

[rmcilroy, 2015-08-26 08:52:00]

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

[commit-bot: I haz the power, 2015-08-26 08:52:09]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314953004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314953004/1

[commit-bot: I haz the power, 2015-08-26 09:02:13]

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

[commit-bot: I haz the power, 2015-08-26 09:02:14]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/...)

[rmcilroy, 2015-08-26 12:54:17]

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

[commit-bot: I haz the power, 2015-08-26 12:54:28]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314953004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314953004/20001

[rmcilroy, 2015-08-26 13:21:03]

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

[rmcilroy, 2015-08-26 13:21:03]

Hannes, could you take a look please? Please let me know if I've missed any
important visitors with this change.

Michi for FYI since I plan to send you the followup CL (but comments welcome).

[commit-bot: I haz the power, 2015-08-26 13:25:52]

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

[commit-bot: I haz the power, 2015-08-26 13:25:53]

Dry run: This issue passed the CQ dry run.

[Hannes Payer (out of office), 2015-08-26 22:19:50]

lgtm, one test nit

https://codereview.chromium.org/1314953004/diff/20001/test/cctest/test-heap.cc
File test/cctest/test-heap.cc (right):

https://codereview.chromium.org/1314953004/diff/20001/test/cctest/test-heap.c...
test/cctest/test-heap.cc:710: i::FLAG_always_compact = true;
The flag you wanna set here is: FLAG_manual_evacuation_candidates_selection =
true;

Please set the flags in the beginning of the test, before initializing the VM.

[rmcilroy, 2015-08-27 10:19:48]

https://codereview.chromium.org/1314953004/diff/20001/test/cctest/test-heap.cc
File test/cctest/test-heap.cc (right):

https://codereview.chromium.org/1314953004/diff/20001/test/cctest/test-heap.c...
test/cctest/test-heap.cc:710: i::FLAG_always_compact = true;
On 2015/08/26 22:19:49, Hannes Payer wrote:
> The flag you wanna set here is: FLAG_manual_evacuation_candidates_selection =
> true;
> 
> Please set the flags in the beginning of the test, before initializing the VM.

Done.

[rmcilroy, 2015-08-27 10:45:23]

The CQ bit was checked by rmcilroy@chromium.org

[rmcilroy, 2015-08-27 10:45:24]

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/1314953004/#ps40001
(title: "Fix test flag.")

[commit-bot: I haz the power, 2015-08-27 10:45:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314953004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314953004/40001

[commit-bot: I haz the power, 2015-08-27 11:11:14]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-08-27 11:12:07]

Patchset 3 (id:??) landed as
https://crrev.com/69ce0f4dc79a5606eec03accd81832aaeaa16075
Cr-Commit-Position: refs/heads/master@{#30404}