[Patch] Fix ac_c99_complex configury

[Gabriel Dos Reis]

Benjamin Kosnik <bkoz@redhat.com> writes:

| > Hmm, I'm confused.  But, yes, I agree we may probably stop 
| > <complex.h> since it now means something different in C99.  
| > Hmm.  C++ + C99 == mess.
| 
| I agree with the C++ vs. C99 sentiment.
| 
| However, it is not exactly clear what you mean WRT backwards/complex.h. 
| 
| I'd like to remove it. Since backwards is searched by default for C++
| compiles, and there is no easy way to remove this from the include
| search path,  it looks like this will be a serious issue WRT libstdc++
| vs. libc.
| 
| Is this what you were implying? I think you are right WRT to the rest
| of the deprecated headers, at least the ones in the C++ standard under
| annex D. We have to keep these for the time being.

Yes.  Let's remove complex.h.

Thanks,

-- Gaby