Fix corner case in optimized code map zapping.

R=jkummerow@chromium.org
TEST=mjsunit/math-floor-part2

Review URL: https://codereview.chromium.org/15743005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14752 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Don't allow copying holes to fields.

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15745006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14753 ce2b1a6d-e550-0410-aec6-3dcde31c8c00