Removing default build of gcc

[Mark Linimon]

On Fri, Jan 25, 2013 at 03:36:15PM -0500, Pedro Giffuni wrote:
> I don't care much about gcc in current.

clang, even on -9, can't build the following:

 - most of kde
 - graphics/GraphicsMagick
 - editors/emacs21
 - www/libxul19

any one of which I would consider showstoppers for making a gcc-less
system.

mcl