[runtime] Simplify CHECK_OBJECT_COERCIBLE.

[runtime] Simplify CHECK_OBJECT_COERCIBLE.

Don't use IS_NULL_OR_UNDEFINED() for CHECK_OBJECT_COERCIBLE() because it
will also return true for undetectable objects, but use IS_NULL() and
IS_UNDEFINED() directly, which will only return true for null or
undefined (which matches the semantics of the abstract operation
CheckObjectCoercible).

R=yangguo@chromium.org

Committed: https://crrev.com/a7d22de460715df97b2b0f4838a505fe3f45ac46
Cr-Commit-Position: refs/heads/master@{#30129}

[Benedikt Meurer, 2015-08-12 10:46:32]

Hey Yang,

This is an obvious one.
Please take a look.

Thanks,
Benedikt

[Yang, 2015-08-12 10:46:50]

On 2015/08/12 10:46:11, Benedikt Meurer wrote:

lgtm.

[Benedikt Meurer, 2015-08-12 10:46:57]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-08-12 10:47:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1287033002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1287033002/1

[commit-bot: I haz the power, 2015-08-12 11:11:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-12 11:11:46]

Patchset 1 (id:??) landed as
https://crrev.com/a7d22de460715df97b2b0f4838a505fe3f45ac46
Cr-Commit-Position: refs/heads/master@{#30129}