Add a separate device memory manager (#6153)

* Add a separate device memory manager

* Still need this

* Device writes are always tracked

* Device writes are always tracked (2)

* Rename more instances of gmm to mm

src/Ryujinx.Graphics.Gpu/Memory/PhysicalMemory.cs

@@ -1,4 +1,5 @@
 using Ryujinx.Cpu;
+using Ryujinx.Graphics.Device;
 using Ryujinx.Graphics.Gpu.Image;
 using Ryujinx.Graphics.Gpu.Shader;
 using Ryujinx.Memory;
@@ -82,6 +83,15 @@ namespace Ryujinx.Graphics.Gpu.Memory
             }
         }
 
+        /// <summary>
+        /// Creates a new device memory manager.
+        /// </summary>
+        /// <returns>The memory manager</returns>
+        public DeviceMemoryManager CreateDeviceMemoryManager()
+        {
+            return new DeviceMemoryManager(_cpuMemory);
+        }
+
         /// <summary>
         /// Gets a host pointer for a given range of application memory.
         /// If the memory region is not a single contiguous block, this method returns 0.