RFR: Fix x86_32 build

[Roman Kennke]

Am 15.06.2018 um 16:02 schrieb Aleksey Shipilev:
> Need to stub out ShenandoahBarrierSetAssembler::generate_shenandoah_wb for !_LP64:
> 
> diff -r e1d9e80ecf2c src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
> --- a/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp	Fri Jun 15 14:17:43
> 2018 +0200
> +++ b/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp	Fri Jun 15 16:00:36
> 2018 +0200
> @@ -859,6 +859,7 @@
>    StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb");
>    address start = __ pc();
> 
> +#ifdef _LP64
>    Label not_done;
> 
>    // We use RDI, which also serves as argument register for slow call.
> @@ -940,7 +941,9 @@
>      __ pop(rdi);
>    }
>    __ ret(0);
> -
> +#else
> +  ShouldNotReachHere();
> +#endif
>    return start;
>  }
> 
> 
> Thanks,
> -Aleksey
> 

Yes. Thanks,
Roman