Initial transform feedback support (#1370)

* Initial transform feedback support

* Some nits and fixes

* Update ReportCounterType and Write method

* Can't change shader or TFB bindings while TFB is active

* Fix geometry shader input names with new naming

Ryujinx.Graphics.Gpu/Constants.cs

@@ -35,6 +35,11 @@ namespace Ryujinx.Graphics.Gpu
         /// </remarks>
         public const int TotalGpStorageBuffers = 16;
 
+        /// <summary>
+        /// Maximum number of transform feedback buffers.
+        /// </summary>
+        public const int TotalTransformFeedbackBuffers = 4;
+
         /// <summary>
         /// Maximum number of render target color buffers.
         /// </summary>