RFR(S): 8211231: BarrierSetC1::generate_referent_check() confuses register allocator

[Roland Westrelin]

> Is it the same thing again?
>  http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2018-September/030705.html
>  https://bugs.openjdk.java.net/browse/JDK-8211084

What about this:

https://bugs.openjdk.java.net/browse/JDK-8211103

Shouldn't the test be skipped?

Roland.