msvc: temporary workaround for C4789 false positive

Source/Core/Core/HW/WiimoteCommon/WiimoteReport.h

@@ -89,7 +89,8 @@ struct OutputReportLeds
 
   u8 rumble : 1;
   u8 ack : 1;
-  u8 : 2;
+  // This field must be named to work around a msvc bug.
+  u8 _padding : 2;
   u8 leds : 4;
 };
 static_assert(sizeof(OutputReportLeds) == 1, "Wrong size");