Bug swiftshader:6

Change-Id: I4a52eda6583a8731fd8e7a8bc15e716a772b8842
Reviewed-on: https://swiftshader-review.googlesource.com/7756Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-on: https://swiftshader-review.googlesource.com/8137Reviewed-by: Alexis Hétu <sugoi@google.com>