EXPERIMENTAL: Metal backend (#441)

This is not a continuation of the Metal backend; this is simply bringing
the branch up to date and merging it as-is behind an experiment.

---------

Co-authored-by: Isaac Marovitz <isaacryu@icloud.com>
Co-authored-by: Samuliak <samuliak77@gmail.com>
Co-authored-by: SamoZ256 <96914946+SamoZ256@users.noreply.github.com>
Co-authored-by: Isaac Marovitz <42140194+IsaacMarovitz@users.noreply.github.com>
Co-authored-by: riperiperi <rhy3756547@hotmail.com>
Co-authored-by: Gabriel A <gab.dark.100@gmail.com>

src/Ryujinx.Graphics.Metal/DisposableSampler.cs

@@ -0,0 +1,22 @@
+using SharpMetal.Metal;
+using System;
+using System.Runtime.Versioning;
+
+namespace Ryujinx.Graphics.Metal
+{
+    [SupportedOSPlatform("macos")]
+    readonly struct DisposableSampler : IDisposable
+    {
+        public MTLSamplerState Value { get; }
+
+        public DisposableSampler(MTLSamplerState sampler)
+        {
+            Value = sampler;
+        }
+
+        public void Dispose()
+        {
+            Value.Dispose();
+        }
+    }
+}