[8] RFR: Fix Windows build after LRB backports

[Roman Kennke]

Yup

Thanks,
Roman

> Current sh/jdk8 build fails on Windows with:
> 
> ...windows\worker\shenandoah-jdk8-windows\build\hotspot\src\share\vm\gc_implementation\shenandoah\shenandoahRuntime.cpp(32)
> : error C2220: warning treated as error - no 'object' file generated
> 
> Fix:
> 
> diff -r 04fce1bceb31 src/share/vm/gc_implementation/shenandoah/shenandoahRuntime.cpp
> --- a/src/share/vm/gc_implementation/shenandoah/shenandoahRuntime.cpp   Wed May 22 10:11:04 2019 +0200
> +++ b/src/share/vm/gc_implementation/shenandoah/shenandoahRuntime.cpp   Wed Oct 23 20:57:12 2019 +0200
> @@ -27,16 +27,18 @@
>  #include "runtime/interfaceSupport.hpp"
>  #include "oops/oop.inline.hpp"
> 
>  void ShenandoahRuntime::write_ref_array_pre_oop_entry(oop* dst, size_t length) {
>    ShenandoahBarrierSet *bs = ShenandoahBarrierSet::barrier_set();
> -  bs->write_ref_array_pre(dst, length, false);
> +  assert(length <= INT_MAX, err_msg("sanity: " SIZE_FORMAT, length));
> +  bs->write_ref_array_pre(dst, (int)length, false);
>  }
> 
>  void ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry(narrowOop* dst, size_t length) {
>    ShenandoahBarrierSet *bs = ShenandoahBarrierSet::barrier_set();
> -  bs->write_ref_array_pre(dst, length, false);
> +  assert(length <= INT_MAX, err_msg("sanity: " SIZE_FORMAT, length));
> +  bs->write_ref_array_pre(dst, (int)length, false);
>  }
> 
>  void ShenandoahRuntime::write_ref_array_post_entry(HeapWord* dst, size_t length) {
>    ShenandoahBarrierSet *bs = ShenandoahBarrierSet::barrier_set();
>    bs->ShenandoahBarrierSet::write_ref_array(dst, length);
> 
> 
> Testing: build (Linux, Windows); hotspot_gc_shenandoah (Linux)
>