[PATCH][4.3] Deprecate -ftrapv

[Richard Kenner]

> > Ada currently has to do this itself, precisely because -ftrapv doesn't
> > work, so it's not the case that Ada "needs" it.
> 
> Well no one "needs" anything in this sense, any interfaced is Turing
> complete so there is *always* a work around deficiencies in the back 
> end. But right now, the "do this itself" is really horribly inefficient:

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.