RFR: Revert commented out Op_CompareAndSwapB/Op_CompareAndSwapS in aarch64.ad

[Roman Kennke]

Apparently I made a mistake and commented out Op_CompareAndSwapB and
Op_CompareAndSwapS in aarch64.ad. Let's revert it to upstream state.

diff --git a/src/hotspot/cpu/aarch64/aarch64.ad
b/src/hotspot/cpu/aarch64/aarch64.ad
--- a/src/hotspot/cpu/aarch64/aarch64.ad
+++ b/src/hotspot/cpu/aarch64/aarch64.ad
@@ -1276,10 +1276,10 @@
     case Op_CompareAndSwapL:
     case Op_CompareAndSwapP:
     case Op_CompareAndSwapN:
+    case Op_CompareAndSwapB:
+    case Op_CompareAndSwapS:
     case Op_ShenandoahCompareAndSwapP:
     case Op_ShenandoahCompareAndSwapN:
- // case Op_CompareAndSwapB:
- // case Op_CompareAndSwapS:
     case Op_GetAndSetI:
     case Op_GetAndSetL:
     case Op_GetAndSetP: