Required adding X and Y flipping to blitter.

Change-Id: Icaac4045ae9419296112464d7ccdde7babb76eb3
Reviewed-on: https://swiftshader-review.googlesource.com/2180Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>