Add support for fragment shader interlock (#2768)

* Support coherent images

* Add support for fragment shader interlock

* Change to tree based match approach

* Refactor + check for branch targets and external registers

* Make detection more robust

* Use Intel fragment shader ordering if interlock is not available, use nothing if both are not available

* Remove unused field

Ryujinx.Graphics.Shader/Decoders/DecodedFunction.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.Graphics.Shader.Decoders
+{
+    class DecodedFunction
+    {
+        private readonly HashSet<DecodedFunction> _callers;
+
+        public bool IsCompilerGenerated => Type != FunctionType.User;
+        public FunctionType Type { get; set; }
+        public int Id { get; set; }
+
+        public ulong Address { get; }
+        public Block[] Blocks { get; private set; }
+
+        public DecodedFunction(ulong address)
+        {
+            Address = address;
+            _callers = new HashSet<DecodedFunction>();
+            Type = FunctionType.User;
+            Id = -1;
+        }
+
+        public void SetBlocks(Block[] blocks)
+        {
+            if (Blocks != null)
+            {
+                throw new InvalidOperationException("Blocks have already been set.");
+            }
+
+            Blocks = blocks;
+        }
+
+        public void AddCaller(DecodedFunction caller)
+        {
+            _callers.Add(caller);
+        }
+
+        public void RemoveCaller(DecodedFunction caller)
+        {
+            if (_callers.Remove(caller) && _callers.Count == 0)
+            {
+                Type = FunctionType.Unused;
+            }
+        }
+    }
+}