When computing the code flags for a megamorphic store IC, we mistakenly
passed a strict_mode variable when an ExtraICState was expected.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/98633005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18202 ce2b1a6d-e550-0410-aec6-3dcde31c8c00