Add Björn Haase's (beta) patch for ATmega256x support, backported
to GCC 4.1.1 by Bernhard Trog.
Add Anatoly Sokolov's patch to support __attribute__((alias)).
ATmega165P, and ATmega169P.
Add the patch mentioned in GCC bug report:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26504
to support DWARF-2 generation, and enable the respective configuration
option.