Support for 'bitwise' integers is one of the main sparse's extension. However, casts to or from pointers to bitwise types can be done without incurring any sort of warnings although such casts can be as wrong as direct casts to or from bitwise integers themselves. Add the corresponding warnings and control them by a new flag -Wbitwise-pointer (defaulting to off as it creates tens of thousands warnings in the kernel). CC: Thiebaud Weksteen <tweek@google.com> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>