[runtime] Unify and fix the strict equality comparison.

[runtime] Unify and fix the strict equality comparison.

Add Object::StrictEquals to unify the implementation of strict equality
comparison in the runtime and the api (the api was already missing a
case for SIMD).  Now we (almost) have a single bottleneck for strict
equality, we just need to reduce the amount of unnecessary complexity
for the code stub.

R=yangguo@chromium.org

Committed: https://crrev.com/9780ddeb9685c30cf64a337446b9a7413a3be64f
Cr-Commit-Position: refs/heads/master@{#30186}

[Benedikt Meurer, 2015-08-16 09:29:58]

Hey Yang,

Another useless builtin removed (and another API bug fixed).
Please take a look.

Thanks,
Benedikt

[Benedikt Meurer, 2015-08-16 10:54:53]

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

[commit-bot: I haz the power, 2015-08-16 10:54:57]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1298603002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1298603002/1

[commit-bot: I haz the power, 2015-08-16 10:58:57]

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

[commit-bot: I haz the power, 2015-08-16 10:58:58]

Dry run: This issue passed the CQ dry run.

[Yang, 2015-08-17 07:13:32]

LGTM.

https://codereview.chromium.org/1298603002/diff/1/src/api.cc
File src/api.cc (left):

https://codereview.chromium.org/1298603002/diff/1/src/api.cc#oldcode3431
src/api.cc:3431: return other->IsUndefined() || other->IsUndetectableObject();
This undetectable check is lost. I guess this is intentional?

[Benedikt Meurer, 2015-08-17 07:59:50]

https://codereview.chromium.org/1298603002/diff/1/src/api.cc
File src/api.cc (left):

https://codereview.chromium.org/1298603002/diff/1/src/api.cc#oldcode3431
src/api.cc:3431: return other->IsUndefined() || other->IsUndetectableObject();
Yes. The code stub has an explicit comment that strict equality doesn't care
about undetectable (otherwise it wouldn't be strict). So the API implementation
was wrong.

[Benedikt Meurer, 2015-08-17 07:59:54]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-08-17 08:00:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1298603002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1298603002/1

[commit-bot: I haz the power, 2015-08-17 08:02:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-17 08:02:24]

Patchset 1 (id:??) landed as
https://crrev.com/9780ddeb9685c30cf64a337446b9a7413a3be64f
Cr-Commit-Position: refs/heads/master@{#30186}