Add AssertSmi() in x64 MacroAssembler::SmiTest().
Add AssertSmi() in x64 MacroAssembler::SmiTest().

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/19647006

git-svn-id: b158db1e4b4ab85d4c9e510fdef4b1e8c614b15b@15790 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh