Improve handling for unmapped GPU resources (#2083)

* Improve handling for unmapped GPU resources

- Fixed a memory tracking bug that would set protection on empty PTEs
- When a texture's memory is (partially) unmapped, all pool references are forcibly removed and the texture must be rediscovered to draw with it. This will also force the texture discovery to always compare the texture's range for a match.
- RegionHandles now know if they are unmapped, and automatically unset their dirty flag when unmapped.
- Partial texture sync now loads only the region of texture that has been modified. Unmapped memory tracking handles cause dirty flags for a texture group handle to be ignored.

This greatly improves the emulator's stability for newer UE4 games.

* Address feedback, fix MultiRange slice

Fixed an issue where the size of the multi-range slice would be miscalculated.

* Update Ryujinx.Memory/Range/MultiRange.cs (feedback)

Co-authored-by: Mary <thog@protonmail.com>

Co-authored-by: Mary <thog@protonmail.com>

Ryujinx.Graphics.Gpu/Image/TextureManager.cs

@@ -715,7 +715,9 @@ namespace Ryujinx.Graphics.Gpu.Image
                     // we know the textures are located at the same memory region.
                     // If they don't, it may still be mapped to the same physical region, so we
                     // do a more expensive check to tell if they are mapped into the same physical regions.
-                    if (overlap.Info.GpuAddress != info.GpuAddress && !_context.MemoryManager.CompareRange(overlap.Range, info.GpuAddress))
+                    // If the GPU VA for the texture has ever been unmapped, then the range must be checked regardless.
+                    if ((overlap.Info.GpuAddress != info.GpuAddress || overlap.ChangedMapping) && 
+                        !_context.MemoryManager.CompareRange(overlap.Range, info.GpuAddress))
                     {
                         continue;
                     }