Updating top-level autoconf to 2.59

[Mike Stump]

On Dec 8, 2006, at 2:02 PM, Steve Ellcey wrote:
> I found that when I set (and exported) CC and then ran the GCC  
> configure & make my build of libstdc++ failed because the build of  
> the libstdc++ library was using my original bootstrap CC

Hum...  from Makefile.in:

BASE_TARGET_EXPORTS = \
         CC="$(CC_FOR_TARGET)"; export CC; \
RAW_CXX_TARGET_EXPORTS = \
         $(BASE_TARGET_EXPORTS) \
         CXX_FOR_TARGET="$(RAW_CXX_FOR_TARGET)"; export  
CXX_FOR_TARGET; \
configure-target-libstdc++-v3:
         $(RAW_CXX_TARGET_EXPORTS) \

is supposed to handle resetting these as I read it, though, I'm not  
en expert.  Does you're Makefile.in have these?