[DAG] Refactor X86 combineVSelectWithAllOnesOrZeros fold into a generic DAG Combine

combineVSelectWithAllOnesOrZeros folds `vselect(cond, 0/-1, X)` and `vselect(cond, X, 0/-1)`  style patterns into logic operations when the cond is the same width and ZeroOrNegativeOneBooleanContent

We should be able to perform this generically in DAGCombiner (with suitable freezing which seems to be missing from the x86 version)