RyuLDN implementation

These changes allow players to matchmake for local wireless using a LDN
server. The network implementation originates from Berry's public TCP
RyuLDN fork. Logo and unrelated changes have been removed.

Additionally displays LDN game status in the game selection window when
RyuLDN is enabled.

Functionality is only enabled while network mode is set to "RyuLDN" in
the settings.

src/Ryujinx.Common/Configuration/Multiplayer/MultiplayerMode.cs

@@ -3,6 +3,7 @@ namespace Ryujinx.Common.Configuration.Multiplayer
     public enum MultiplayerMode
     {
         Disabled,
+        LdnRyu,
         LdnMitm,
     }
 }

src/Ryujinx.Common/Memory/StructArrayHelpers.cs

@@ -803,18 +803,6 @@ namespace Ryujinx.Common.Memory
         public Span<T> AsSpan() => MemoryMarshal.CreateSpan(ref _e0, Length);
     }
 
-    public struct Array256<T> : IArray<T> where T : unmanaged
-    {
-        T _e0;
-        Array128<T> _other;
-        Array127<T> _other2;
-        public readonly int Length => 256;
-        public ref T this[int index] => ref AsSpan()[index];
-
-        [Pure]
-        public Span<T> AsSpan() => MemoryMarshal.CreateSpan(ref _e0, Length);
-    }
-
     public struct Array140<T> : IArray<T> where T : unmanaged
     {
         T _e0;
@@ -828,6 +816,18 @@ namespace Ryujinx.Common.Memory
         public Span<T> AsSpan() => MemoryMarshal.CreateSpan(ref _e0, Length);
     }
 
+    public struct Array256<T> : IArray<T> where T : unmanaged
+    {
+        T _e0;
+        Array128<T> _other;
+        Array127<T> _other2;
+        public readonly int Length => 256;
+        public ref T this[int index] => ref AsSpan()[index];
+
+        [Pure]
+        public Span<T> AsSpan() => MemoryMarshal.CreateSpan(ref _e0, Length);
+    }
+
     public struct Array384<T> : IArray<T> where T : unmanaged
     {
         T _e0;

src/Ryujinx.Common/Utilities/NetworkHelpers.cs

@@ -1,6 +1,7 @@
 using System.Buffers.Binary;
 using System.Net;
 using System.Net.NetworkInformation;
+using System.Runtime.InteropServices;
 
 namespace Ryujinx.Common.Utilities
 {
@@ -65,6 +66,11 @@ namespace Ryujinx.Common.Utilities
             return (targetProperties, targetAddressInfo);
         }
 
+        public static bool SupportsDynamicDns()
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+        }
+
         public static uint ConvertIpv4Address(IPAddress ipAddress)
         {
             return BinaryPrimitives.ReadUInt32BigEndian(ipAddress.GetAddressBytes());