8266440: Shenandoah: TestReferenceShortcutCycle.java test failed on AArch64

Reviewed-by: aph

Author: zhengyu123

src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp

@@ -242,7 +242,14 @@ void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm,
   __ ldrb(rscratch2, gc_state);
 
   // Check for heap stability
-  __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, heap_stable);
+  if (is_strong) {
+    __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, heap_stable);
+  } else {
+    Label lrb;
+    __ tbnz(rscratch2, ShenandoahHeap::WEAK_ROOTS_BITPOS, lrb);
+    __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, heap_stable);
+    __ bind(lrb);
+  }
 
   // use r1 for load address
   Register result_dst = dst;