Texture Sync, incompatible overlap handling, data flush improvements. (#2971)

* Initial test for texture sync

* WIP new texture flushing setup

* Improve rules for incompatible overlaps

Fixes a lot of issues with Unreal Engine games. Still a few minor issues (some caused by dma fast path?) Needs docs and cleanup.

* Cleanup, improvements

Improve rules for fast DMA

* Small tweak to group together flushes of overlapping handles.

* Fixes, flush overlapping texture data for ASTC and BC4/5 compressed textures.

Fixes the new Life is Strange game.

* Flush overlaps before init data, fix 3d texture size/overlap stuff

* Fix 3D Textures, faster single layer flush

Note: nosy people can no longer merge this with Vulkan. (unless they are nosy enough to implement the new backend methods)

* Remove unused method

* Minor cleanup

* More cleanup

* Use the More Fun and Hopefully No Driver Bugs method for getting compressed tex too

This one's for metro

* Address feedback, ASTC+ETC to FormatClass

* Change offset to use Span slice rather than IntPtr Add

* Fix this too

Ryujinx.Graphics.OpenGL/PersistentBuffers.cs

@@ -94,6 +94,21 @@ namespace Ryujinx.Graphics.OpenGL
             return new ReadOnlySpan<byte>(_bufferMap.ToPointer(), size);
         }
 
+        public unsafe ReadOnlySpan<byte> GetTextureData(TextureView view, int size, int layer, int level)
+        {
+            EnsureBuffer(size);
+
+            GL.BindBuffer(BufferTarget.PixelPackBuffer, _copyBufferHandle);
+
+            int offset = view.WriteToPbo2D(0, layer, level);
+
+            GL.BindBuffer(BufferTarget.PixelPackBuffer, 0);
+
+            Sync();
+
+            return new ReadOnlySpan<byte>(_bufferMap.ToPointer(), size).Slice(offset);
+        }
+
         public unsafe ReadOnlySpan<byte> GetBufferData(BufferHandle buffer, int offset, int size)
         {
             EnsureBuffer(size);