3.6.1 nomination: 'optnone' should not disable DAG combiner

[Tom Stellard]

Owen, what do you think?

On Wed, Apr 01, 2015 at 12:22:41AM +0000, Robinson, Paul wrote:
> I'm requesting r233153 and r233584 get merged to the 3.6 branch.
> 233153 causes 'optnone' _not_ to disable the entire DAG combiner,
> because disabling the combiner can lead to instruction-selection 
> crashes. 233584 is the test for that patch.
> Thanks,
> --paulr
>