This is a first implementation of the transform feedback
primitives written query.

It passes available related dEQP tests (more tests will be
available when transform feedback is fully implemented).

Change-Id: Iaee97e3e2e853174b7f22836f72dabede1ed04c1
Reviewed-on: https://swiftshader-review.googlesource.com/4912Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>