Make -Werror possible to control on a per-warning-class basis. While
I was fixing up that code anyway, merge the handling of the -w, -W and
[warning] argument and directives.
Furthermore, make *all* warnings suppressible; any warning that isn't
categorized now belong to category "other". However, for cleanliness
sake an "other" option does not get listed in the warning messages.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
b2047cbb98