Use fast_sqrt instead of std::sqrt in simulators.

Use fast_sqrt instead of std::sqrt in simulators.

This prevents clang from inlining and returning inconsistent results.

R=bmeurer@chromium.org
BUG=v8:3802
LOG=N

Committed: https://crrev.com/f38e48be60df22320035db330c7275d6dff4d6c2
Cr-Commit-Position: refs/heads/master@{#26158}

[Yang, 2015-01-20 13:04:41]

See test bot runs here: https://codereview.chromium.org/863583003

[Benedikt Meurer, 2015-01-20 13:05:10]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-01-20 13:05:10]

lgtm

[commit-bot: I haz the power, 2015-01-20 13:05:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/831393006/1

[commit-bot: I haz the power, 2015-01-20 13:08:59]

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

[commit-bot: I haz the power, 2015-01-20 13:09:00]

Try jobs failed on following builders:
  v8_presubmit on tryserver.v8
(http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/65)

[Yang, 2015-01-20 13:10:12]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2015-01-20 13:10:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/831393006/1

[Yang, 2015-01-20 13:15:25]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2015-01-20 13:15:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/831393006/20001

[commit-bot: I haz the power, 2015-01-20 13:53:39]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-20 13:53:53]

Patchset 2 (id:??) landed as
https://crrev.com/f38e48be60df22320035db330c7275d6dff4d6c2
Cr-Commit-Position: refs/heads/master@{#26158}