Move VarHandle fences to unreachable intrinsics.

These were erroneously moved to unimplemented intrinsics in
    https://android-review.googlesource.com/1372099 .

Test: m
Bug: 71781600
Change-Id: Ic348ec1be92e7db8722575dd44f22826e770cc75
diff --git a/compiler/optimizing/intrinsics.h b/compiler/optimizing/intrinsics.h
index 96f178e..48a1035 100644
--- a/compiler/optimizing/intrinsics.h
+++ b/compiler/optimizing/intrinsics.h
@@ -285,7 +285,12 @@
 UNREACHABLE_INTRINSIC(Arch, StringLength)                       \
 UNREACHABLE_INTRINSIC(Arch, UnsafeLoadFence)                    \
 UNREACHABLE_INTRINSIC(Arch, UnsafeStoreFence)                   \
-UNREACHABLE_INTRINSIC(Arch, UnsafeFullFence)
+UNREACHABLE_INTRINSIC(Arch, UnsafeFullFence)                    \
+UNREACHABLE_INTRINSIC(Arch, VarHandleFullFence)                 \
+UNREACHABLE_INTRINSIC(Arch, VarHandleAcquireFence)              \
+UNREACHABLE_INTRINSIC(Arch, VarHandleReleaseFence)              \
+UNREACHABLE_INTRINSIC(Arch, VarHandleLoadLoadFence)             \
+UNREACHABLE_INTRINSIC(Arch, VarHandleStoreStoreFence)
 
 template <typename IntrinsicLocationsBuilder, typename Codegenerator>
 bool IsCallFreeIntrinsic(HInvoke* invoke, Codegenerator* codegen) {