alpha switched to gcc 4.8

[Martin Husemann <martin%duskware.de@localhost>]

I just switched alpha over to gcc-4.8 - you may want to remove your
objdir before doing the next build (at least tools/gcc and external/gpl3/gcc).

I plan to look at fenv.h support for alpha next and will try to get the
number of atf test failures down (most of them are in floating point
stuff, some are pthread related).

Martin