Oilpan: move Location to the oilpan heap.

Also add missing transition type handling for [PutForwards] over
garbage collected interface types.

R=haraken@chromium.org
BUG=340522

Review URL: https://codereview.chromium.org/196133029

git-svn-id: svn://svn.chromium.org/blink/trunk@169538 bbb929c8-8fbe-4397-9dbb-9b2b20218538