PPC: [compiler] Drop the CompareNilIC.

PPC: [compiler] Drop the CompareNilIC.

Port 666aec0348c8793e61c8633dee7ad29a514239ba

Original commit message:
    Since both null and undefined are also marked as undetectable now, we
    can just test that bit instead of having the CompareNilIC try to collect
    feedback to speed up the general case (without the undetectable bit
    being used).

    Drive-by-fix: Update the type system to match the new handling of
    undetectable in the runtime.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/546ea6b8393a894f07597ade5ec1c7db02c1e425
Cr-Commit-Position: refs/heads/master@{#34266}

[MTBrandyberry, 2016-02-24 18:56:14]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2016-02-24 18:56:28]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1733663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1733663003/1

[commit-bot: I haz the power, 2016-02-24 19:15:25]

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

[commit-bot: I haz the power, 2016-02-24 19:15:26]

Dry run: This issue passed the CQ dry run.

[JoranSiu, 2016-02-24 22:23:13]

On 2016/02/24 19:15:26, commit-bot: I haz the power wrote:
> Dry run: This issue passed the CQ dry run.

lgtm

[MTBrandyberry, 2016-02-24 22:29:53]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2016-02-24 22:30:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1733663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1733663003/1

[commit-bot: I haz the power, 2016-02-24 22:32:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-24 22:32:40]

Description was changed from

==========
PPC: [compiler] Drop the CompareNilIC.

Port 666aec0348c8793e61c8633dee7ad29a514239ba

Original commit message:
    Since both null and undefined are also marked as undetectable now, we
    can just test that bit instead of having the CompareNilIC try to collect
    feedback to speed up the general case (without the undetectable bit
    being used).

    Drive-by-fix: Update the type system to match the new handling of
    undetectable in the runtime.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=
==========

to

==========
PPC: [compiler] Drop the CompareNilIC.

Port 666aec0348c8793e61c8633dee7ad29a514239ba

Original commit message:
    Since both null and undefined are also marked as undetectable now, we
    can just test that bit instead of having the CompareNilIC try to collect
    feedback to speed up the general case (without the undetectable bit
    being used).

    Drive-by-fix: Update the type system to match the new handling of
    undetectable in the runtime.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/546ea6b8393a894f07597ade5ec1c7db02c1e425
Cr-Commit-Position: refs/heads/master@{#34266}
==========

[commit-bot: I haz the power, 2016-02-24 22:32:41]

Patchset 1 (id:??) landed as
https://crrev.com/546ea6b8393a894f07597ade5ec1c7db02c1e425
Cr-Commit-Position: refs/heads/master@{#34266}

[MTBrandyberry, 2016-02-26 21:24:43]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1736253003/ by mbrandy@us.ibm.com.

The reason for reverting is: Original commit reverted..