[Arm64] Remove irregular vector not handling
[Arm64] Remove irregular vector not handling

cshung/coreclr,ruben-ayrapetyan/coreclr,mmitche/coreclr,krk/coreclr,ruben-ayrapetyan/coreclr,wtgodbe/coreclr,poizan42/coreclr,mmitche/coreclr,ruben-ayrapetyan/coreclr,poizan42/coreclr,ruben-ayrapetyan/coreclr,mmitche/coreclr,yizhang82/coreclr,poizan42/coreclr,poizan42/coreclr,wtgodbe/coreclr,poizan42/coreclr,cshung/coreclr,poizan42/coreclr,mmitche/coreclr,mmitche/coreclr,krk/coreclr,wtgodbe/coreclr,wtgodbe/coreclr,wtgodbe/coreclr,krk/coreclr,mmitche/coreclr,cshung/coreclr,ruben-ayrapetyan/coreclr,krk/coreclr,krk/coreclr,wtgodbe/coreclr,cshung/coreclr,yizhang82/coreclr,yizhang82/coreclr,yizhang82/coreclr,krk/coreclr,ruben-ayrapetyan/coreclr,cshung/coreclr,yizhang82/coreclr,yizhang82/coreclr,cshung/coreclr