Fixing bugs in promotion of elements transitions (r1175). - Fixed invalid...

Fixing bugs in promotion of elements transitions (r1175). - Fixed invalid memory access when reading enum-cache from descriptor array with elements transitions but 0 real descriptors. - Fixed infinite recursion in the intrusive map iterator when visiting elements transitions. - Properly cached non-fastmode elements transitions.

Review URL: https://chromiumcodereview.appspot.com/10565030

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@11841 ce2b1a6d-e550-0410-aec6-3dcde31c8c00