Merged r17569 into 3.22 branch.

Make HCapturedObjects non-deletable for DCE.

BUG=v8:2987
R=jkummerow@chromium.org, kasperl@chromium.org

Review URL: https://codereview.chromium.org/76223003

git-svn-id: https://v8.googlecode.com/svn/branches/3.22@17871 ce2b1a6d-e550-0410-aec6-3dcde31c8c00