[PATCH][4.3] Deprecate -ftrapv

[Robert Dewar]

Richard Kenner wrote:
> Clearly.  My point was that Ada doesn't need a *broken* -ftrapv.  So if
> there's no hope of fixing it, we might as well deprecate it.

Sure, but right now we have the start of a constructive discussion of
how to fix it, so the best thing would be to contribute positively to
that and see where it gets us :-)

No one needs a broken anything, but we have to be careful about
deprecating things just because they are broken! We have to be
really sure that there's no hope of fixing it. In this case, the
feature would be very useful in debugging C (especially given
GCC's aggressive use of the undefinedness of arithmetic overflow
in C, it would definitely be nice to be able to test at -O0 -ftrapv
and have this find overflows).