Change x86 default arch for 4.5?

[Gerald Pfeifer]

On Mon, 22 Feb 2010, Erik Trulsson wrote:
> As for the relative hurts.  Code compiled for a newer CPU (making use
> of newer instructions) will not run at all on older CPUs not supporting
> those newer instructions.  Much hurt there.
> 
> On the other hand code compiled for an older CPU that is run a newer
> CPU will run just fine, if slightly slower than they could have due
> to not making use of new instructions in the newer CPU.

That can well be seen as a point for _making_ the change:  when it
fails, the user/admin knows there is a need to adjust, whereas silent
degradation will continue to make look GCC bad and hurt its traction
and adoption (as Steven and others have experienced).

Gerald