[v3] Fix stringbuf handling of NUL characters

[Benjamin Kosnik]

> > it'll be tonight/tomorrow before I post a working test.

Ok.

> Sigh.  Somebody on this list mentioned some interesting parameters to
> pass when configuring/building GDB that would make debugging C++/libstdc++
> easier, or at least possible.  Anyone remember what they are?

--with-dwarf2

you might want to try CVS gdb + binutils (the 'src' module). Also, I've
been told that if you face west while stepping into functions, and throw a
pinch of sand from the appropriate caribbean beach over your right
shoulder, things go much smoother.

-benjamin