Updated comparison of GCC releases

[Vladimir Makarov]

Some people asked me to update GCC release comparison page on 
http://vmakarov.fedorapeople.org/spec/

I've added 4.3, new target x86_64 and SPECFP2000 for the comparison.  
You can find it on http://vmakarov.fedorapeople.org/spec/

Vlad