PPC: [simd.js] Single SIMD128_VALUE_TYPE for all Simd128Values.

PPC: [simd.js] Single SIMD128_VALUE_TYPE for all Simd128Values.

Port f4c079d450a5990639b295d40a3d1663d70412d6

Original commit message:
    There's no need to have one InstanceType per SIMD primitive type (this
    will not scale long-term).  Also reduce the amount of code duplication
    and make it more robust wrt adding new SIMD types.

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

Committed: https://crrev.com/a1733785cfd5f328fb8506e2768a89932c57c7da
Cr-Commit-Position: refs/heads/master@{#30392}

[john.yan, 2015-08-26 19:08:37]

lgtm

[MTBrandyberry, 2015-08-26 19:10:00]

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

[commit-bot: I haz the power, 2015-08-26 19:10:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1312513004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1312513004/1

[commit-bot: I haz the power, 2015-08-26 19:10:20]

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

[commit-bot: I haz the power, 2015-08-26 19:10:21]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[dstence, 2015-08-26 19:22:41]

lgtm

[MTBrandyberry, 2015-08-26 19:23:00]

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

[commit-bot: I haz the power, 2015-08-26 19:23:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1312513004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1312513004/1

[commit-bot: I haz the power, 2015-08-26 19:50:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-26 19:50:58]

Patchset 1 (id:??) landed as
https://crrev.com/a1733785cfd5f328fb8506e2768a89932c57c7da
Cr-Commit-Position: refs/heads/master@{#30392}