Add: Sector, an spanized buffer/queue.

The CDROM doesn't need a real tail/head queue/enqueue function, as it only needs to one shot the fill of the sector and then dequeue.
Also Queue<T> doesn't have a Span<T> constructor and can't clean and "addAll" without allocating a new internal buffer array.
This little util class aims to try to avoid allocations as well as simplify the DMAs out.

ProjectPSX/Devices/CDROM/Sector.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace ProjectPSX.Devices.CdRom {
+    class Sector {
+
+        private const int BYTES_PER_SECTOR_RAW = 2352;
+        private byte[] sectorBuffer = new byte[BYTES_PER_SECTOR_RAW];
+
+        private int pointer;
+        private int size;
+
+        public void fillWith(Span<byte> data) {
+            pointer = 0;
+            size = data.Length;
+            var dest = sectorBuffer.AsSpan();
+            data.CopyTo(dest);
+        }
+
+        public ref byte readByte() {
+            ref var data = ref MemoryMarshal.GetArrayDataReference(sectorBuffer);
+            return ref Unsafe.Add(ref data, pointer++);
+        }
+
+        public Span<uint> read(int size) { //size from dma comes as u32
+            var dma = sectorBuffer.AsSpan().Slice(pointer, size * 4);
+            pointer += size * 4;
+            return MemoryMarshal.Cast<byte, uint>(dma);
+        }
+
+        public Span<byte> read() => sectorBuffer.AsSpan().Slice(0, size);
+
+        public bool hasData() => pointer < size;
+
+        public void clear() {
+            pointer = 0;
+            size = 0;
+        }
+
+    }
+}