cpplib: fix -Wtrigraphs double warnings

[Zack Weinberg]

On Thu, Nov 23, 2000 at 08:47:47AM -0800, Geoff Keating wrote:
> "Zack Weinberg" <zackw@Stanford.EDU> writes:
> 
> > On Wed, Nov 22, 2000 at 08:22:28PM +0000, Neil Booth wrote:
> > > And a testcase (Wtrigraphs.c):-
> > 
> > I'm not sure this will fail in the presence of the bug.  The existing
> > trigraphs test should've picked it up, but it didn't.
> > 
> > I don't know what to do about it, though; it's a design problem with
> > dg.exp.  The "excess errors" test doesn't distinguish between one copy
> > of an error mesage, and multiple copies.
> 
> Are you sure you have the latest dejagnu?
> 
> I'm sure I've seen test failures in the regression tester caused
> by this.

I have the 20000714 snapshot.  Should I be using something newer?

zw