RFR: 9+8u: MacroAssembler and ShenandoahBarrierSet reference x86_64 registers

[Roman Kennke]

Am 20.03.2017 um 18:59 schrieb Aleksey Shipilev:
> Hi,
>
> Another batch of i586 build failure fixes. Conditionalize shared Shenandoah code
> with _LP64 where they reference x86_64 registers. This allows us to build:
>   http://cr.openjdk.java.net/~shade/shenandoah/build/noregs-i586/webrev.01/
>
> This affects both 9 and 8u.
>
> Testing: hotspot_gc_shenandoah for both 9 and 8u.
>
> -Aleksey
>
>
Yes. Thanks for finding+fixing it!

Roman