Handle null receiver in sloppy mode in %GetFrameDetails.

R=jarin@chromium.org
BUG=405922
LOG=N

Review URL: https://codereview.chromium.org/492303006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23312 ce2b1a6d-e550-0410-aec6-3dcde31c8c00