Set code on the SharedFunctionInfo before creating the function.

BUG=
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/238773009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20873 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Make sure to clear any previously collected field maps.

TEST=http://www.chaostoperfection.com/
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/246963003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20874 ce2b1a6d-e550-0410-aec6-3dcde31c8c00