Reland VectorICs: ia32 store ics need a virtual register.

Reland VectorICs: ia32 store ics need a virtual register.

(reason for revert/reland: patch incorrectly left --vector-stores flag
 on, helpfully revealing some gcstress issues to look at, but they
 don't need to block this CL).

Some pretty hacky code was used to carry out the tail-call
handler dispatch on ia32 vector stores due to a lack
of free registers. It really tanks performance. A better
approach is to use a virtual register on the isolate.

BUG=
TBR=jkummerow@chromium.org, vogelheim@chromium.org

Committed: https://crrev.com/1e00bb57a2969e3e428a1d552116752a95c06022
Cr-Commit-Position: refs/heads/master@{#30737}

[mvstanton, 2015-09-15 09:39:24]

mvstanton@chromium.org changed reviewers:
+ vogelheim@chromium.org

[mvstanton, 2015-09-15 09:39:24]

Hi guys,
Here is the patch from yesterday, this time without the offending
--vector-stores flag turned on. I'll go ahead and submit, though suitably
chastened!
--Michael

[Jakob Kummerow, 2015-09-15 09:48:33]

rubberstamp LGTM

[vogelheim, 2015-09-15 09:53:21]

lgtm (src/snapshot)

[mvstanton, 2015-09-15 09:56:57]

The CQ bit was checked by mvstanton@chromium.org

[commit-bot: I haz the power, 2015-09-15 09:57:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1346573002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1346573002/1

[commit-bot: I haz the power, 2015-09-15 10:14:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-15 10:14:39]

Patchset 1 (id:??) landed as
https://crrev.com/1e00bb57a2969e3e428a1d552116752a95c06022
Cr-Commit-Position: refs/heads/master@{#30737}