vacid0/sparse array: added VC for array access within bounds
vacid0/sparse array: added VC for array access within bounds

douglas-larocca/why3,ssaavedra/why3,ssaavedra/why3,jpdeplaix/why3,douglas-larocca/why3,douglas-larocca/why3,jpdeplaix/why3,jpdeplaix/why3,ssaavedra/why3