Move solution and projects to src

src/Ryujinx.Common/Memory/SpanWriter.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Common.Memory
+{
+    public ref struct SpanWriter
+    {
+        private Span<byte> _output;
+
+        public int Length => _output.Length;
+
+        public SpanWriter(Span<byte> output)
+        {
+            _output = output;
+        }
+
+        public void Write<T>(T value) where T : unmanaged
+        {
+            MemoryMarshal.Cast<byte, T>(_output)[0] = value;
+            _output = _output.Slice(Unsafe.SizeOf<T>());
+        }
+
+        public void Write(ReadOnlySpan<byte> data)
+        {
+            data.CopyTo(_output.Slice(0, data.Length));
+            _output = _output.Slice(data.Length);
+        }
+
+        public void WriteAt<T>(int offset, T value) where T : unmanaged
+        {
+            MemoryMarshal.Cast<byte, T>(_output.Slice(offset))[0] = value;
+        }
+
+        public void WriteAt(int offset, ReadOnlySpan<byte> data)
+        {
+            data.CopyTo(_output.Slice(offset, data.Length));
+        }
+
+        public void Skip(int size)
+        {
+            _output = _output.Slice(size);
+        }
+    }
+}