Add support for alpha to coverage dithering (#3069)

* Add support for alpha to coverage dithering

* Shader cache version bump

* Fix wrong alpha register

* Ensure support buffer is cleared

* New shader specialization based approach

Ryujinx.Graphics.Shader/IGpuAccessor.cs

@@ -34,6 +34,15 @@ namespace Ryujinx.Graphics.Shader
         /// <returns>Span of the memory location</returns>
         ReadOnlySpan<ulong> GetCode(ulong address, int minimumSize);
 
+        /// <summary>
+        /// Queries whenever the alpha-to-coverage dithering feature is enabled.
+        /// </summary>
+        /// <returns>True if the feature is enabled, false otherwise</returns>
+        bool QueryAlphaToCoverageDitherEnable()
+        {
+            return false;
+        }
+
         /// <summary>
         /// Queries the binding number of a constant buffer.
         /// </summary>