Bug swiftshader:6

Change-Id: I7d32d12081f4a704f4731cfa29c0eadf75a43d49
Reviewed-on: https://swiftshader-review.googlesource.com/7738Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-on: https://swiftshader-review.googlesource.com/8130Reviewed-by: Alexis Hétu <sugoi@google.com>