This continues in applying the CHECK_DATA_CORRUPTION tests where appropriate, and pulling similar CONFIGs under the same check. Most notably, this adds the checks to refcount_t so that system builders can Oops their kernels when encountering a potential refcounter attack. (And so now the LKDTM tests for refcount issues pass correctly.)
I'd love to get people's Acks in case this needs to go through the kspp tree instead of something else, like maybe -mm if that seems better. Thanks, -Kees
