RFR: Fix aarch64

[Aleksey Shipilev]

On 09/08/2017 12:26 PM, Roman Kennke wrote:
> I tried to run some applications with Shenandoah on aarch64 and ran into
> an assert in the interpreter. Apparently we got some overlap of
> registers in the interpreter barriers. Changing rscratch2 to rscratch1
> (the same registers that are used in the corresponding G1 barriers) then
> it all works.
> 
> Tests: hotspot_gc_shenandoah (modulo 1 test that does timeout for other
> reasons)
> 
> http://cr.openjdk.java.net/~rkennke/fixaarch64/webrev.00/
> 
> Ok?

OK.

-Aleksey