PATCH: Add __frame_state_for for gcc 3.0.1

[Joe Buck]

> > It IMHO must work (although one cannot mix pre-G++ 3.0 and G++ 3.0 C++
> > libraries together, one should be able to mix G++ 3.0 C++ libraries with
> > pre-GCC 3.0 C libraries and vice versa, and C libraries can have unwinding
> > info). So it needs to be debugged why it cannot find it.
> 
> I think it is a doable. Basically, we have to put a complete set of
> frame unwind functions in glibc, which supports the mixed v2 and v3
> frames. It may take a while. I wish they were in gcc :-(.

I'm sure it's doable, but you then have to carry around the cruft forever.
Given the fact that we won't support mixing gcc2 and gcc3 C++ code, how
does this benefit a user that has gcc3 and a gcc3-compiled glibc?  He/she
would have to have some other C code, compiled with gcc2, that has
exception handling, and then mix it with gcc3 C++ code.  Are we solving
a problem that really exists, or only a theoretical problem?