This is similar to https://bugs.openjdk.org/browse/JDK-8293351
Add a second temporary register for BarrierSetAssembler::load_at GC API on riscv64.
Today G1 and Shenandoah uses a second temporary register. This will also be the case for generational ZGC.
Add a second temporary register for BarrierSetAssembler::load_at GC API on riscv64.
Today G1 and Shenandoah uses a second temporary register. This will also be the case for generational ZGC.