X87: fix the sqrt issue.

X87: fix the sqrt issue.

       The test mjsunit/regress/regress-sqrt compares the result of Math.sqrt function
       when using full-compiler and turbofan/crankshaft compiler seperately. But according
       to glibc bug fixing(https://sourceware.org/bugzilla/show_bug.cgi?id=14032). The
       glibc implementation of std::sqrt() (It is invoked in the generated code when
       full-compiler is used.) will change since glibc 2.19.

       In order to keep consistence of Math.sqrt translation in turbofan compiler
       and the pass of mjsunit/regress/regress-sqrt. we translate the Math.sqrt func
       according to the same fix in glibc change.  If the GLIBC version >=2.19, we will
       set the precision to Double. (the original is extended-double).

       This fix is to fix the same issue in https://codereview.chromium.org/606403002 for
       crankshaft. This fix may be ported for crankshaft too.

BUG=

Committed: https://crrev.com/d43bbd068dcdb7c4ad46d2a7cc6d303343ef58f8
Cr-Commit-Position: refs/heads/master@{#31592}

[chunyang.dai, 2015-10-27 05:55:44]

chunyang.dai@intel.com changed reviewers:
+ weiliang.lin@intel.com

[chunyang.dai, 2015-10-27 05:55:45]

PTAL

[chunyang.dai, 2015-10-27 05:59:55]

Patchset #1 (id:1) has been deleted

[Weiliang, 2015-10-27 07:55:23]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-10-27 07:55:23]

lgtm

[commit-bot: I haz the power, 2015-10-27 07:55:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1425763002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1425763002/20001

[commit-bot: I haz the power, 2015-10-27 08:14:12]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2015-10-27 08:14:29]

Patchset 1 (id:??) landed as
https://crrev.com/d43bbd068dcdb7c4ad46d2a7cc6d303343ef58f8
Cr-Commit-Position: refs/heads/master@{#31592}