RFR: remove obsolete code

[Aleksey Shipilev]

On 08/16/2018 11:06 AM, Roland Westrelin wrote:
> 
>> And that thing is actually ConP:
>>
>> #  assert(wb->Opcode() == Op_ShenandoahWriteBarrier) failed: expect write barrier: ConP
>>
>> Applying this partial reversal helps to avoid the assert:
>>   http://cr.openjdk.java.net/~shade/shenandoah/revert-c2-const.patch
> 
> Right. Dropping that stuff was wrong.

So, I can push this partial reversal patch then?

-Aleksey