Partial shadow header patch (was Re: still problems withlibstdcxx-v3 and -ansi)

[Benjamin Kosnik]

Ok. I've had a chance to look at this now.

Thanks. It's a patch in the right direction......

Re: _ISOC99_SOURCE

It appears as if /usr/include/features.h is the one that sets up all of
this stuff. _GNU_SOURCE does not automatically define _ISOC99_SOURCE,
contrary to the C library manual. Thus, I've defined it in the
libstdc++-v3 Makefiles...

I've also added a bunch of ISOC99 math float and long doubles to
shadow/bits/std_cmath.h. 

This completely cleans up src/complex.cc, removing most of the need for
the FCT macro: Yeah!

I'm still working my way through the library, getting everything to
compile. I've made a bunch of changes to get the io bits working.

Steven, can you please post a ChangeLog entry?

more later,
benjamin