PATCH to toplevel Makefile.in check-c++ target

[DJ Delorie]

> Won't it be merged there?  Or do you mean instead of the trunk?  I
> figured that it was a small enough change that it didn't matter.

Now that the branch/merge nightmare has begun, I don't know what to
recommend.  Send email to Zack.  The toplevel files have changed
significantly in bib; there's bound to be merge issues, even with
small changes like this.