Mask queries could return negative values when only positive values are accepted, so a clamp was added to prevent returning negative values. Change-Id: Ib151573fff54604567b83736163b8fe748c749f8 Reviewed-on: https://swiftshader-review.googlesource.com/4743Tested-by: Alexis Hétu <sugoi@google.com> Reviewed-by: Nicolas Capens <capn@google.com>
