Double field values need sNaN -> qNaN canonicalization.

Double field values need sNaN -> qNaN canonicalization.

Also fix mjsunit/regress/regress-undefined-nan to ensure that we are
testing transfer via xmm registers by forcing the transfer to be in an
optimized function.

BUG=v8:3839
LOG=n
R=jkummerow@chromium.org

Committed: https://crrev.com/0381acf7b32893f3ec8b097ec269d6743682905a
Cr-Commit-Position: refs/heads/master@{#26213}

[Benedikt Meurer, 2015-01-22 06:13:03]

PTAL

[Jakob Kummerow, 2015-01-22 08:15:21]

lgtm

[Benedikt Meurer, 2015-01-22 08:15:36]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-01-22 08:16:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/863153002/1

[commit-bot: I haz the power, 2015-01-22 08:36:10]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-22 08:36:18]

Patchset 1 (id:??) landed as
https://crrev.com/0381acf7b32893f3ec8b097ec269d6743682905a
Cr-Commit-Position: refs/heads/master@{#26213}