Revert "Use %_IsSmi instead of %MaxSmi."
Revert "Use %_IsSmi instead of %MaxSmi."

This reverts r17983.

TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/79263005

git-svn-id: b158db1e4b4ab85d4c9e510fdef4b1e8c614b15b@17984 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

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