[DAGCombiner] Generalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)...

[DAGCombiner] Generalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2) combine to work on non-splat vectors

The knownbits_mask_or_shuffle_uitofp change is interesting - shuffle combines manage to kick in, removing the AND constant mask load. For targets with fast-variable-shuffle this should reduce further to VPOR+VPSHUFB+VCVTDQ2PS.

llvm-svn: 321279