[vector-api][X86] Intrinsic creation for missing cases of iotaShuffle API

[Vladimir Ivanov]

> In loopTransform.cpp I would encourage you to make your change more incremental.
> Your change re-orders the existing predicate terms while inserting the new term at the
> beginning.  It is more conventional to add new logic at the end, while retaining the flow
> of the old logic.  I think breaking the lines *is* a good idea, so something like this is good:
> 
> -      if (opc == Op_StoreP || opc == Op_StoreN || opc == Op_StoreNKlass || opc == Op_StoreCM) {
> +-      if (opc == Op_StoreVector || opc == Op_StoreP ||
> ++      if (opc == Op_StoreP ||
> +           opc == Op_StoreN || opc == Op_StoreNKlass ||
> +-          opc == Op_StoreCM) {
> ++          opc == Op_StoreCM || opc == Op_StoreVector) {

Also, Jatin, please, clarify what was the motivation to do this change 
in the first place.

> You can still use two lambdas if you want for the fallback, one for each value
> of wrap.  But I suspect using one would be cleaner.
> 
> (I’ll defer to Vladimir on this; he may have more information about what’s right here.)

 From compiler perspective it doesn't matter. So, I'd vote for the 
option which makes the code more readable.

Best regards,
Vladimir Ivanov