[GPU] Add more shader instructions, add support for rgb565 textures

Ryujinx.Graphics/Gal/Shader/ShaderIrMetaTex.cs

@@ -0,0 +1,12 @@
+namespace Ryujinx.Graphics.Gal.Shader
+{
+    class ShaderIrMetaTex : ShaderIrMeta
+    {
+        public int Elem { get; private set; }
+
+        public ShaderIrMetaTex(int Elem)
+        {
+            this.Elem = Elem;
+        }
+    }
+}