ARM/MIPS compilation error.

Due to an error during platform porting.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/91583002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18106 ce2b1a6d-e550-0410-aec6-3dcde31c8c00