Allow nfloat to be in the ObjCRuntime namespace, and make it work for…

… Xamarin.MacCatalyst.dll as well.

Ref: xamarin/xamarin-macios#13092
Ref: mono/mono#21261

src/mono/mono/mini/mini-native-types.c

@@ -372,6 +372,8 @@ mono_class_is_magic_assembly (MonoClass *klass)
  return TRUE;
  if (!strcmp ("Xamarin.WatchOS", aname))
  return TRUE;
+ if (!strcmp ("Xamarin.MacCatalyst", aname))
+ return TRUE;
  /* regression test suite */
  if (!strcmp ("builtin-types", aname))
  return TRUE;
@@ -427,7 +429,7 @@ mono_class_is_magic_float (MonoClass *klass)
  if (!mono_class_is_magic_assembly (klass))
  return FALSE;
 
- if (strcmp ("System", m_class_get_name_space (klass)) != 0)
+ if (strcmp ("System", m_class_get_name_space (klass)) != 0 && strcmp ("ObjCRuntime", m_class_get_name_space (klass)) != 0)
  return FALSE;
 
  if (strcmp ("nfloat", m_class_get_name (klass)) == 0) {