Sampling byte4 data currently reads 8 bytes for unpacking purposes. Allocate 4 more bytes to prevent reading outside the image, even though it's unused data. Bug 21935792 Change-Id: I162fb3f3575131cedb008f82ef5170e773719e41 Reviewed-on: https://swiftshader-review.googlesource.com/3572Reviewed-by: Alexis Hétu <sugoi@google.com> Tested-by: Nicolas Capens <capn@google.com> Reviewed-by: Nicolas Capens <capn@google.com>
