An object should only be promoted to the old generation if it survived a scavenge operation.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/345523002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21915 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Make our FOO::cast methods const.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/347073003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21916 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Simplify access checks performed by GetOwnProperty

BUG=
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/339553002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21917 ce2b1a6d-e550-0410-aec6-3dcde31c8c00