Update OpNone.cs for Math.Round()
Update OpNone.cs for Math.Round()

OS says Math.Round() is not implemented without the changes. It should work now!
fanoI/Cosmos,jp2masa/Cosmos,CosmosOS/Cosmos,tgiphil/Cosmos,trivalik/Cosmos,fanoI/Cosmos,CosmosOS/Cosmos,zarlo/Cosmos,zarlo/Cosmos,zarlo/Cosmos,jp2masa/Cosmos,tgiphil/Cosmos,CosmosOS/Cosmos,jp2masa/Cosmos,fanoI/Cosmos,zarlo/Cosmos,CosmosOS/Cosmos,tgiphil/Cosmos,trivalik/Cosmos,trivalik/Cosmos