[DAG] combineShiftAnd1ToBitTest - match "and (srl (not X), C)), 1 --> (and X, 1<<C) == 0" patterns

combineShiftAnd1ToBitTest already matches "and (not (srl X, C)), 1 --> (and X, 1<<C) == 0" patterns, but we can end up with situations where the not is before the shift.

Part of some yak shaving for D127115 to generalise the "xor (X >> ShiftC), XorC --> (not X) >> ShiftC" fold.