GPU: Swap bindings array instead of copying (#4003)

* GPU: Swap bindings array instead of copying

Reduces work on UpdateShaderState. Now the cost is a few reference moves for arrays, rather than copying data.

Downside: bindings arrays are no longer readonly.

* Micro optimisation

* Add missing docs

* Address Feedback

Ryujinx.Graphics.Gpu/Shader/CachedShaderProgram.cs

@@ -24,6 +24,11 @@ namespace Ryujinx.Graphics.Gpu.Shader
         /// </summary>
         public CachedShaderStage[] Shaders { get; }
 
+        /// <summary>
+        /// Cached shader bindings, ready for placing into the bindings manager.
+        /// </summary>
+        public CachedShaderBindings Bindings { get; }
+
         /// <summary>
         /// Creates a new instance of the shader bundle.
         /// </summary>
@@ -37,6 +42,7 @@ namespace Ryujinx.Graphics.Gpu.Shader
             Shaders = shaders;
 
             SpecializationState.Prepare(shaders);
+            Bindings = new CachedShaderBindings(shaders.Length == 1, shaders);
         }
 
         /// <summary>