This CL starts using positive array indices instead of negative array indices
for the PropertyCallbackInfo and FunctionCallbackInfo fields. Also, the indices
match now, so they can be unified in the next step.

BUG=
R=dcarney@chromium.org, mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/24488006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17015 ce2b1a6d-e550-0410-aec6-3dcde31c8c00