Add missing map check to optimized f.apply(...)

This is a cutdown version of https://codereview.chromium.org/346473002/, which aimed to fix f.call and f.apply. Optimized f.call was removed by r21887, this is what was left.

BUG=386034
LOG=N
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/348623002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21907 ce2b1a6d-e550-0410-aec6-3dcde31c8c00