In order to resolve the sqrt precision issue described in https://codereview.chromium.org/1425763002/.
  we change the implementation of CreateSqrtFunction() implementation of X87 so that the optimize compiler
  and full-compiler implementation are unified.

R=weiliang.lin@intel.com
BUG=

Review URL: https://codereview.chromium.org/1417553007

Cr-Commit-Position: refs/heads/master@{#31625}