RFR(XS): 8218468: Load barrier slow path node should be MachTypeNode

[Per Liden]

Looks good!

/Per

On 4/16/19 10:44 AM, Nils Eliasson wrote:
> Hi,
> 
> We have a number of assert failures in RunThese testing. This is caused 
> by  LoadBarrierSlowReg and LoadBarrierWeakSlowReg not being MachTypeNodes.
> 
> This patches fixes that.
> 
> I am also adding includes for ZGC and Shenandoah.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8218468
> 
> Webrev: http://cr.openjdk.java.net/~neliasso/8218468/webrev.01/
> 
> Please review,
> 
> Nils Eliasson
>