[x86] Allow (v)divsd->(v)mulsd to execute in parallel.

[x86] Allow (v)divsd->(v)mulsd to execute in parallel.

This tweak was already present in CrankShaft for the non-AVX case. As it
turns out, it's also relevant even with AVX. Now the same optimization
is applied in case of TurboFan as well.

R=dcarney@chromium.org

Committed: https://crrev.com/e21f9ab42b90bb125380a62f2f54071a705bdf92
Cr-Commit-Position: refs/heads/master@{#27774}

[Benedikt Meurer, 2015-04-13 08:03:19]

Hey Dan,

This is straight forward port of the existing CS optimization. Please take a
look.

Thanks,
Benedikt

[dcarney, 2015-04-13 08:11:08]

lgtm

do we know for which cpus this matters?  instead of the comment, maybe something
like EmitMoveForRegisterRenamer() or something would be better?

[Benedikt Meurer, 2015-04-13 08:23:54]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-04-13 08:23:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1081033003/1

[commit-bot: I haz the power, 2015-04-13 08:25:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-13 08:25:45]

Patchset 1 (id:??) landed as
https://crrev.com/e21f9ab42b90bb125380a62f2f54071a705bdf92
Cr-Commit-Position: refs/heads/master@{#27774}