PPC: [compiler] Introduce StringEqualStub and StringNotEqualStub.

PPC: [compiler] Introduce StringEqualStub and StringNotEqualStub.

Port 2689548e38c68bb6294fed5e2d83feec67e3a1f4

Original commit message:
    These new stubs perform exactly the same job as the string equality case
    for the CompareIC, but are platform independent and usable outside of
    fullcodegen and Crankshaft. We use them in the StrictEqualStub and the
    StrictNotEqualStub instead of falling back to the runtime immediately
    for String comparisons, and we also use them in TurboFan to perform
    String equality or inequality comparisons.

    These stubs currently handle only internalized and one byte strings w/o
    going to C++, but it should be easy to add support for more string cases
    later, i.e. utilizing already flattened cons strings or comparing two
    byte strings as well.

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

Committed: https://crrev.com/d61b8cee8c35a0f02814419aa254f4821fbfa69e
Cr-Commit-Position: refs/heads/master@{#34462}

[MTBrandyberry, 2016-03-03 16:05:46]

PTAL

[JoranSiu, 2016-03-03 16:08:10]

On 2016/03/03 16:05:46, MTBrandyberry wrote:
> PTAL

lgtm

[MTBrandyberry, 2016-03-03 16:17:13]

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

[commit-bot: I haz the power, 2016-03-03 16:17:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1763723002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1763723002/1

[commit-bot: I haz the power, 2016-03-03 16:33:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-03 16:34:06]

Description was changed from

==========
PPC: [compiler] Introduce StringEqualStub and StringNotEqualStub.

Port 2689548e38c68bb6294fed5e2d83feec67e3a1f4

Original commit message:
    These new stubs perform exactly the same job as the string equality case
    for the CompareIC, but are platform independent and usable outside of
    fullcodegen and Crankshaft. We use them in the StrictEqualStub and the
    StrictNotEqualStub instead of falling back to the runtime immediately
    for String comparisons, and we also use them in TurboFan to perform
    String equality or inequality comparisons.

    These stubs currently handle only internalized and one byte strings w/o
    going to C++, but it should be easy to add support for more string cases
    later, i.e. utilizing already flattened cons strings or comparing two
    byte strings as well.

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

to

==========
PPC: [compiler] Introduce StringEqualStub and StringNotEqualStub.

Port 2689548e38c68bb6294fed5e2d83feec67e3a1f4

Original commit message:
    These new stubs perform exactly the same job as the string equality case
    for the CompareIC, but are platform independent and usable outside of
    fullcodegen and Crankshaft. We use them in the StrictEqualStub and the
    StrictNotEqualStub instead of falling back to the runtime immediately
    for String comparisons, and we also use them in TurboFan to perform
    String equality or inequality comparisons.

    These stubs currently handle only internalized and one byte strings w/o
    going to C++, but it should be easy to add support for more string cases
    later, i.e. utilizing already flattened cons strings or comparing two
    byte strings as well.

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

Committed: https://crrev.com/d61b8cee8c35a0f02814419aa254f4821fbfa69e
Cr-Commit-Position: refs/heads/master@{#34462}
==========

[commit-bot: I haz the power, 2016-03-03 16:34:11]

Patchset 1 (id:??) landed as
https://crrev.com/d61b8cee8c35a0f02814419aa254f4821fbfa69e
Cr-Commit-Position: refs/heads/master@{#34462}