RFR: Fix references to missing SharedRuntime::g1_wb_pre in AArch64

[Roman Kennke]

Ok. Thanks!
Roman

> AArch64 still fails to build, because SharedRuntime::g1_wb_pre is gone.
> 
> Fix:
> 
> diff -r 8ac23a282d76 src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
> --- a/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Tue Jun 12
> 09:10:52 2018 +0200
> +++ b/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Tue Jun 12
> 09:24:52 2018 +0200
> @@ -177,9 +177,9 @@
> 
>    if (expand_call) {
>      assert(pre_val != c_rarg1, "smashed arg");
> -    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
> +    __ super_call_VM_leaf(CAST_FROM_FN_PTR(address,
> ShenandoahBarrierSet::write_ref_field_pre_entry), pre_val, thread);
>    } else {
> -    __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
> +    __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahBarrierSet::write_ref_field_pre_entry),
> pre_val, thread);
>    }
> 
>    __ pop(saved, sp);
> @@ -564,7 +564,7 @@
>    __ bind(runtime);
>    __ push_call_clobbered_registers();
>    __ load_parameter(0, pre_val);
> -  __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
> +  __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahBarrierSet::write_ref_field_pre_entry),
> pre_val, thread);
>    __ pop_call_clobbered_registers();
>    __ bind(done);
> 
> 
> Thanks,
> -Aleksey
>