Fix android_arm.debug after r20051

The ConstantPoolBuilder stores RelocInfo in an stl::vector, therefore RelocInfo
cannot subclass BASE_EMBEDDED.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/253923005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21056 ce2b1a6d-e550-0410-aec6-3dcde31c8c00