When the CR Fields selected by SVP64-Augmented `BI` is marked as scalar,
then as the usual SVP64 rules apply:
-the loop ends at the first element tested, after taking
+the Vector loop ends at the first element tested, after taking
predication into consideration. Thus, also as usual, when a predicate mask is
given, and `BI` marked as scalar, and `sz` is zero, srcstep
skips forward to the first non-zero predicated element, and only that