[PATCH] Fix various minor gimple-ssa-sprintf.c issues

[Martin Sebor]

>> What I would be even more grateful for is a review of the error
>> prone parts like those that caused the bootstrap failure.  I.e.,
>> any lingering assumptions about integer sizes between the host
>
> I must say I'm surprised you do all your computations in HOST_WIDE_INT,
> rather than say in wide_int, then you could just compare against
> TYPE_{MIN,MAX}_VALUE (TYPE_DOMAIN (integer_type_node)) instead of inventing
> a function for that.  As for the warn_* vs. flag_* stuff, it just looked
> that the warn_* is tested in lots of functions invoked even for the return
> length folding, so it is much harder to prove whether it works properly or
> not.

Well, chalk that up to my ignorance of a better/more appropriate
API.  I'll be happy to switch to using it if it simplifies things.
Thanks for the tip!

Martin