They make assumptions about elementskind of arrays based on allocation site
feedback. This feedback is highly dependent on mementos, unrooted objects
placed behind arrays in the heap meant to live until the next scavenge.
GcStress does many more gcs than normal, and wrecks havoc with this kind
of test.
BUG=
R=hpayer@chromium.org
Review URL: https://codereview.chromium.org/23449042
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16832 ce2b1a6d-e550-0410-aec6-3dcde31c8c00