Vulkan: Migrate buffers between memory types to improve GPU performance (#4540)

* Initial implementation of migration between memory heaps

- Missing OOM handling
- Missing `_map` data safety when remapping
  - Copy may not have completed yet (needs some kind of fence)
  - Map may be unmapped before it is done being used. (needs scoped access)
- SSBO accesses are all "writes" - maybe pass info in another way.
- Missing keeping map type when resizing buffers (should this be done?)

* Ensure migrated data is in place before flushing.

* Fix issue where old waitable would be signalled.

- There is a real issue where existing Auto<> references need to be replaced.

* Swap bound Auto<> instances when swapping buffer backing

* Fix conversion buffers

* Don't try move buffers if the host has shared memory.

* Make GPU methods return PinnedSpan with scope

* Storage Hint

* Fix stupidity

* Fix rebase

* Tweak rules

Attempt to sidestep BOTW slowdown

* Remove line

* Migrate only when command buffers flush

* Change backing swap log to debug

* Address some feedback

* Disallow backing swap when the flush lock is held by the current thread

* Make PinnedSpan from ReadOnlySpan explicitly unsafe

* Fix some small issues

- Index buffer swap fixed
- Allocate DeviceLocal buffers using a separate block list to images.

* Remove alternative flags

* Address feedback

Ryujinx.Graphics.OpenGL/Buffer.cs

@@ -55,11 +55,14 @@ namespace Ryujinx.Graphics.OpenGL
                 (IntPtr)size);
         }
 
-        public static unsafe ReadOnlySpan<byte> GetData(OpenGLRenderer renderer, BufferHandle buffer, int offset, int size)
+        public static unsafe PinnedSpan<byte> GetData(OpenGLRenderer renderer, BufferHandle buffer, int offset, int size)
         {
+            // Data in the persistent buffer and host array is guaranteed to be available
+            // until the next time the host thread requests data.
+
             if (HwCapabilities.UsePersistentBufferForFlush)
             {
-                return renderer.PersistentBuffers.Default.GetBufferData(buffer, offset, size);
+                return PinnedSpan<byte>.UnsafeFromSpan(renderer.PersistentBuffers.Default.GetBufferData(buffer, offset, size));
             }
             else
             {
@@ -69,7 +72,7 @@ namespace Ryujinx.Graphics.OpenGL
 
                 GL.GetBufferSubData(BufferTarget.CopyReadBuffer, (IntPtr)offset, size, target);
 
-                return new ReadOnlySpan<byte>(target.ToPointer(), size);
+                return new PinnedSpan<byte>(target.ToPointer(), size);
             }
         }