Bug swiftshader:6

Change-Id: Iba0a4904e99f7323c7e2044be03bb7dd950929d9
Reviewed-on: https://swiftshader-review.googlesource.com/7951Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-on: https://swiftshader-review.googlesource.com/8157Reviewed-by: Alexis Hétu <sugoi@google.com>