RFA: fix PR 7286

[Tom Tromey]

>>>>> "Joseph" == Joseph S Myers <joseph@codesourcery.com> writes:

>> According to C99, such a constant is never unsigned, but instead is of
>> the next wider type (from int, long, and long long) which can
>> represent its value.

Joseph> Note that this is something that changed in C99; in C90 such constants 
Joseph> (wider than signed long) would be unsigned.

Thanks.

This does raise the question of what C variant gdb targets, or ought
to target.  We could even have them all, with "set lang c99".  The
same question arises for C++.

I think if we are going to have a single variant for a given language,
then gdb ought to follow the most recently published standard.

Tom