Revert "Do not use unnecessary `membarrier()` on x86." am: 6c2275d43d am: 9fb3470099 am: 4f8179dba0

Original change: https://android-review.googlesource.com/c/platform/art/+/2394352

Change-Id: Ie43601e42365acc46491041d7df77291a20039d0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>