Slight improvement of object printer for maps.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/14969030

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14689 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Shift additional_index by element_shift_size, not shift_size.

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14629021

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14690 ce2b1a6d-e550-0410-aec6-3dcde31c8c00