implement MemoryManagerHostTracked.GetReadOnlySequence() (#6695)

* implement `MemoryManagerHostTracked.GetReadOnlySequence()`, fixes crashes on game starts on MacOS

* whitespace fixes

* whitespace fixes

* add missing call to `SignalMemoryTracking()`

* adjust call to `SignalMemoryTracking()``

* don't use GetPhysicalAddressMemory()

* add newline for consistency

src/Ryujinx.Memory/NativeMemoryManager.cs

@@ -8,6 +8,11 @@ namespace Ryujinx.Memory
         private readonly T* _pointer;
         private readonly int _length;
 
+        public NativeMemoryManager(nuint pointer, int length)
+            : this((T*)pointer, length)
+        {
+        }
+
         public NativeMemoryManager(T* pointer, int length)
         {
             _pointer = pointer;