make -Wbitwise operational again
The flag -Wbitwise have no effect since patch
02a886bfa
("Introduce keyword driven attribute parsing"): the corresponding
checks are now always done.
Fix that by reintroducing it in the same way as it was:
ignore the bitwise attribute if the flag is not set.
It's less invasive that checking the flag at each place
an corresponding warning is emitted.
Also, to not perturb the current situation the flag is now
enabled by default.
Reported-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>