Fix test serialization path for windows.

This work-around takes into account that MSVS doesn't build to "out".

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/202923003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20261 ce2b1a6d-e550-0410-aec6-3dcde31c8c00