MIPS: Vector ICs: platform support for vector-based stores.

MIPS: Vector ICs: platform support for vector-based stores.

Port of https://codereview.chromium.org/1328603003/

Original commit message:
The last changes for vector store functionality, they are in 3 areas:

1) The new vector [keyed] store code stubs - implementation.
2) IC and handler compiler adjustments
3) Odds and ends. A change in ast.cc, a test update, a small Oracle fix.

BUG=

patch from issue 1326763004 at patchset 1 (http://crrev.com/1326763004#ps1)

[paul.l..., 2015-09-03 05:19:52]

paul.lind@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, balazs.kilvady@imgtec.com, mvstanton@chromium.org

[paul.l..., 2015-09-03 05:19:53]

Hey Michael - here are MIPS ports, l-g-t-m for inclusion in your
https://codereview.chromium.org/1328603003/

[mvstanton, 2015-09-03 08:29:06]

On 2015/09/03 05:19:53, paul.l... wrote:
> Hey Michael - here are MIPS ports, l-g-t-m for inclusion in your
> https://codereview.chromium.org/1328603003/

Thanks tons Paul! Man, that was fast..