| * Important: iropt: Make sure XorV128 and XorV256 of identical |

| * add more iteration in test cases |

| * math_UNPCKxPS_128: use xIsH ? InterleaveHI32x4 : InterleaveLO32x |

| I think this is safe w.r.t. the backend |

| * math_UNPCKxPD_128: ditto |

| * math_UNPCKxPD_256: split into 128 bit chunks and use math_UNPCKxPD_128 |

| * for many (all?) of the vector shift-by-imm cases (pre-existing as |

| well as AVX), out of range shifts are not handled properly and only |

| work I think because the host happens to have the same semantics. |