PPC/s390: [turbofan] Introduce Float64Pow and NumberPow operators.

PPC/s390: [turbofan] Introduce Float64Pow and NumberPow operators.

Port e607e12ea0a706a0b8cb109e95f923426094dc09

Original commit message:
    Introduce a new machine operator Float64Pow that for now is backed by
    the existing MathPowStub to start the unification of Math.pow, and at
    the same time address the main performance issue that TurboFan still has
    with the imaging-darkroom benchmark in Kraken.

    Also migrate the Math.pow builtin itself to a TurboFan builtin and
    remove a few hundred lines of hand-written platform code for special
    handling of the fullcodegen Math.pow version.

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

BUG=v8:3599, v8:5086, v8:5157
LOG=N

Committed: https://crrev.com/05638b9d1d70ae55c1c7ac934a5f511095dc866d
Cr-Commit-Position: refs/heads/master@{#37344}

[JaideepBajwa, 2016-06-28 17:27:25]

PTAL

[john.yan, 2016-06-28 17:30:50]

lgtm

[JaideepBajwa, 2016-06-28 17:31:19]

The CQ bit was checked by bjaideep@ca.ibm.com

[commit-bot: I haz the power, 2016-06-28 17:31:27]

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, 2016-06-28 17:58:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-28 18:01:51]

Description was changed from

==========
PPC/s390: [turbofan] Introduce Float64Pow and NumberPow operators.

Port e607e12ea0a706a0b8cb109e95f923426094dc09

Original commit message:
    Introduce a new machine operator Float64Pow that for now is backed by
    the existing MathPowStub to start the unification of Math.pow, and at
    the same time address the main performance issue that TurboFan still has
    with the imaging-darkroom benchmark in Kraken.

    Also migrate the Math.pow builtin itself to a TurboFan builtin and
    remove a few hundred lines of hand-written platform code for special
    handling of the fullcodegen Math.pow version.

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

BUG=v8:3599,v8:5086,v8:5157
LOG=N
==========

to

==========
PPC/s390: [turbofan] Introduce Float64Pow and NumberPow operators.

Port e607e12ea0a706a0b8cb109e95f923426094dc09

Original commit message:
    Introduce a new machine operator Float64Pow that for now is backed by
    the existing MathPowStub to start the unification of Math.pow, and at
    the same time address the main performance issue that TurboFan still has
    with the imaging-darkroom benchmark in Kraken.

    Also migrate the Math.pow builtin itself to a TurboFan builtin and
    remove a few hundred lines of hand-written platform code for special
    handling of the fullcodegen Math.pow version.

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

BUG=v8:3599,v8:5086,v8:5157
LOG=N

Committed: https://crrev.com/05638b9d1d70ae55c1c7ac934a5f511095dc866d
Cr-Commit-Position: refs/heads/master@{#37344}
==========

[commit-bot: I haz the power, 2016-06-28 18:01:52]

Patchset 1 (id:??) landed as
https://crrev.com/05638b9d1d70ae55c1c7ac934a5f511095dc866d
Cr-Commit-Position: refs/heads/master@{#37344}