Bug 511227: Set CPU_ARCH appropriately.  The patch is contributed by chmeeedalf@gmail.com.  r=wtc.
Bug 511227: Set CPU_ARCH appropriately.  The patch is contributed by
chmeeedalf@gmail.com.  r=wtc.

ekr/nss-old,nmav/nss,nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old,ekr/nss-old,ekr/nss-old,nmav/nss,nmav/nss,ekr/nss-old,nmav/nss,ekr/nss-old,nmav/nss