<ext/slist> breakage

[Gabriel Dos Reis]

Hi,

While trying to compile a software found at

	http://www.gang.umass.edu/software/cmclab/

(yes, I need to draw naughty pictures :-), after a long difficult
struggle against non-portable code I realise that the following

	#include <ext/slist>
	
	int main() { }

no longer works :-(

I think the problem was introduced with the SGI-centric macro hackery
removal.  I locally worked around the problem by #includeing
several bits (type_traits.h, stl_alloc.h, std_stddefs.h).

Phil, could you look into that please?  The disease might be wider
than I think.

-- Gaby