Fix the IsTheHole bug.

For Double constant of non nan, object_ may be uninitialized.

(This patch comes from weiliang.lin@intel.com )

BUG=
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/565183004

Patch from Chunyang Dai <chunyang.dai@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00