Implement support for page sizes > 4KB (#4252)

* Implement support for page sizes > 4KB

* Check and work around more alignment issues

* Was not meant to change this

* Use MemoryBlock.GetPageSize() value for signal handler code

* Do not take the path for private allocations if host supports 4KB pages

* Add Flags attribute on MemoryMapFlags

* Fix dirty region size with 16kb pages

Would accidentally report a size that was too high (generally 16k instead of 4k, uploading 4x as much data)

Co-authored-by: riperiperi <rhy3756547@hotmail.com>

Ryujinx.Memory/MemoryBlock.cs

@@ -440,4 +440,4 @@ namespace Ryujinx.Memory
 
         private static void ThrowInvalidMemoryRegionException() => throw new InvalidMemoryRegionException();
     }
-}
+}