Bug swiftshader:13

Change-Id: I054d0521ecbb1959c5c19b6fa54f76707f4e49c9
Reviewed-on: https://swiftshader-review.googlesource.com/7358Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>