Use filler maps for folded allocations when verify heap is turned on.
Use filler maps for folded allocations when verify heap is turned on.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/18863011

git-svn-id: b158db1e4b4ab85d4c9e510fdef4b1e8c614b15b@15636 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh