[vector] java doc for iota()

[Viswanathan, Sandhya]

Hi Paul,

There is another place, where the java doc may need to change.

The Java implementation of iota() performs full wrapping when "wrap" is passed as true, otherwise it does partial wrapping.
Whereas the java doc below in VectorShuffle.java doesn't mention partial wrapping at all:
    /**
     * Creates a shuffle using source indexes set to sequential
     * values starting from {@code start} and stepping
     * by the given {@code step}.
     * If {@code wrap} is true, also reduce each index (as if
     * by {@link VectorShuffle#wrapIndex(int) wrapIndex})
     * to the valid range {@code [0..VLENGTH-1]}.
     * <p>
     * This method returns the value of the expression
     * {@code VectorShuffle.fromOp(species, i -> R(start + i * step))},
     * where {@code R} is {@code wrapIndex} if {@code wrap} is true,
     * and is the identity function otherwise.
     * ......
     */
public static <E> VectorShuffle<E> iota(VectorSpecies<E> species,
                                            int start, int step,
                                            boolean wrap) {

There is mention of partial wrapping in java doc of fromValues in VectorShuffle.java:
    *
     * <p> For each shuffle lane, where {@code N} is the shuffle lane
     * index, the {@code N}th index value is validated
     * against the species {@code VLENGTH}, and (if invalid)
     * is partially wrapped to an exceptional index in the
     * range {@code [-VLENGTH..-1]}.

Best Regards,
Sandhya